#truth potion

Across the room, Lily Evans shut her eyes for one long, exhausted moment.

Mary Macdonald leaned against Marlene McKinnon’s shoulder and whispered, “Ten galleons says Slughorn finally kills one of them today.”

“Only ten?” Marlene asked. “Coward.”

Near the Slytherin table, Barty Crouch Jr. was sitting half-sideways in his seat with the kind of sharp, entertained stillness that meant he was fully awake now. Evan Rosier lounged beside him, all careless posture and watchful eyes. Pandora Rosier was doodling something in the corner of her parchment that looked suspiciously like Slughorn with bat wings. Dorcas Meadowes, sitting nearby with her chin in one hand, looked like she’d already decided this lesson was a write-off and had made peace with that.

Regulus Black, two seats down, was actually brewing properly.

Of course he was.

His sleeves were rolled just enough to keep them clear of the work, dark hair falling slightly forward as he bent over the cauldron, expression cool and distant and so infuriatingly composed that it made half the room look even more unruly by comparison. He moved with quiet precision, long fingers steady on the ladle, eyes fixed on the slow silver whirlpool in the potion as though the rest of the class simply did not exist.

Which, in fairness, to Regulus, it probably didn’t.

Slughorn’s eyes swept the room once more and landed, with the inevitability of a curse, on the Marauders.

He inhaled.

Smiled.

And that was far more frightening than if he’d shouted.

“Well,” he said warmly, “since Mr Potter and Mr Black seem to believe themselves so entertaining, perhaps we might put that energy to productive use.”

James straightened at once. “Professor, I’d love to help, obviously, but I’m really more of a behind-the-scenes artistic mind.”

“Terrible stage fright,” Sirius added solemnly. “Tragic, honestly.”

Peter shot up a hand so fast he nearly smacked himself in the face. “I’m allergic.”

Slughorn blinked. “Allergic.”

“Yes, sir.”

“To what, exactly?”

Peter glanced at the board, where the ingredient list for Veritaserum Practice Draft Version Three was still written in chalk.

“…moonseed.”

Pandora made a choked sound that might have been a laugh.

Slughorn folded his hands over his stomach and regarded Peter with the expression of a man staring at a particularly stupid hat. “Mr Pettigrew. There is no moonseed in this potion.”

Peter paused. “Then… that other thing.”

“Powdered sage?”

“Yes.”

“You are not allergic to sage.”

Peter wilted. “No, sir.”

“Thought not.”

Slughorn’s smile sharpened. “Then perhaps Mr Lupin will do us the honour, since he is the only one at that table who occasionally behaves like he has been raised by civilisation.”

The entire room turned.

Remus looked up slowly.

“No,” he said.

Slughorn clasped his hands tighter. “Yes.”

“Professor—”

“Mr Lupin.”

James sat up immediately. “Actually, I volunteer as tribute.”

“You do not.”

Sirius pointed across the room. “Can’t we use Snivellus?”

“No,” said Slughorn.

“Barty, then?” James suggested. “He looks medically unwell enough to survive it.”

“I’d ask what that means,” Barty drawled, “but I don’t respect your opinion enough to bother.”

Remus turned to his friends with betrayal written all over his face. “Help me.”

James gave him a solemn pat on the shoulder. “You’re the bravest of us.”

Sirius nodded. “The most expendable.”

Peter whispered, “I’ll miss you.”

“You are all horrific,” Remus muttered.

But Slughorn was already beckoning him forward.

“Come along, come along. It’s only a demonstration.”

“That is never a reassuring sentence,” Remus said darkly, pushing back his chair.

He made his way to the front through an immediate storm of interest. Heads lifted. Elbows planted. Even people who had been half-asleep moments earlier were suddenly wide awake. A lesson involving one of the Marauders being forcibly dosed with a truth potion was, quite frankly, the best thing that had happened to this class all term.

Remus stopped beside Slughorn’s desk and eyed the small crystal vial set there like it personally offended him.

“It’s a controlled classroom batch,” Slughorn said. “Mild. Temporary. Quite safe.”

“Wonderful,” Remus said. “That really eases my spirit.”

“Drink.”

Remus took the vial, glanced back once at his table—James grinning, Sirius already vibrating with the anticipation of violence, Peter trying not to look delighted—and then, with the air of a man stepping off a cliff, tipped the potion back and swallowed.

The room went dead quiet.

Remus grimaced. “That is vile.”

Slughorn looked pleased. “How many fingers am I holding up?”

“Three.”

“What is your name?”

“Remus John Lupin.”

“Your house?”

“Gryffindor.”

“Are you presently in my Potions class?”

Remus stared at him. “Unfortunately.”

A ripple of laughter broke across the room.

Slughorn’s moustache twitched. “Do you feel compelled to answer truthfully?”

“Yes.”

“Can you lie?”

“No.”

“Excellent.”

That one word changed everything.

The class straightened like wolves hearing a dinner bell ring.

Slughorn turned slowly to face them all, hands spread in gracious invitation. “Since the potion is clearly effective, we may as well turn this into an educational experience. You may each ask a question.”

For one dazzling second there was silence.

Then the room erupted.

“Oh, this is beautiful,” Sirius whispered.

James was on his feet so fast his stool tipped over backwards.

Mary slapped both hands over her mouth and then failed completely to contain her grin.

Marlene actually pounded the desk once with delight.

Alice Fortescue sat up straighter, eyes bright. Frank Longbottom leaned in at once, already laughing. Fabian and Gideon Prewett exchanged the exact same dangerous expression that meant everyone nearby should brace themselves. Lily folded her arms, but she was smiling despite herself.

At the Slytherin side, Barty looked almost reverent. Pandora dropped her quill entirely. Dorcas turned fully in her seat. Evan, who had thus far affected the lazy boredom of a man above all this, was now openly interested.

Regulus glanced up from his parchment.

Only once.

Only briefly.

But he looked.

And that alone felt like the opening crack in a dam.

James raised both hands. “Me first.”

“Of course,” Remus said flatly.

James beamed. “What is the most humiliating thing Sirius has ever done?”

Sirius gasped. “Traitor.”

Remus answered instantly. “He once spent three straight hours trying to look seductive in a mirror after a fifth-year Hogsmeade trip because a waitress called him pretty.”

The class screamed.

Sirius clutched at his chest. “That is slander.”

“It’s not slander if it happened.”

“You swore never to speak of that.”

“You made finger guns at your own reflection.”

Marlene nearly slid off her stool laughing. Mary was fully bent over the table. Fabian slapped Gideon’s arm hard enough to make the vial rack shake.

James was wiping tears from his face. “Oh, that is monstrous. That is the best day of my life.”

Sirius pointed at Remus with righteous fury. “You are dead to me.”

“Ask another one,” Peter pleaded. “Ask another.”

Lily raised her hand with eerie calm. “What is the stupidest thing James has ever done for attention?”

James turned to her, horrified. “Evans.”

Remus didn’t even hesitate. “Second year. He tried to fake a mysterious curse scar because he thought it would make him look dangerous.”

The dungeon exploded.

“No!” James shouted.

“Yes,” Remus said. “He scratched his own shoulder with a quill, then spent all day leaning dramatically against walls.”

“I was twelve!”

“You called it your burden.”

Peter folded over onto the desk, cackling. Sirius was making a sound like a dying engine.

Lily put both hands over her face, laughing helplessly. “Oh my God.”

Slughorn, to his credit, had stopped pretending this was educational and was now just enjoying himself.

Gideon raised a hand without waiting to be called on. “What about Peter?”

Peter froze. “No.”

Fabian grinned. “Yeah. What about Peter?”

Remus sighed through his nose. “Peter cries when dogs in books die.”

“A lot of people cry when dogs die in books!” Peter yelped.

“He cried at a painting once.”

“It looked sad!”

“It was a bowl of fruit.”

The room lost it again.

Pandora had tears in her eyes. Barty was laughing hard enough that he’d gone silent, which was somehow worse. Dorcas put her head down on the desk. Even Regulus’s mouth had shifted very slightly at one corner, not quite a smile but close enough that Sirius saw it and nearly lost his mind from triumph.

“Again,” Sirius demanded, wiping his eyes. “Tell us something about Moony.”

Remus went still.

The class noticed.

And the mood changed at once—not darker, exactly, but sharper. More intent. More predatory.

Because this was the good part now.

Mary leaned forward. “What’s the most embarrassing thing about you?”

Remus stared at the opposite wall. “There are so many.”

“Pick one,” said Marlene gleefully.

Remus exhaled. “I once wrote an entire page of notes in the margin of a library book because I forgot it wasn’t mine.”

“That’s not embarrassing,” Alice protested. “That’s deeply on brand.”

“Another one,” James said at once. “A worse one.”

Remus closed his eyes. “I rehearse conversations in advance.”

“That’s adorable,” Lily said.

“I rehearse arguments I lost three years ago and win them in the bath.”

The laughter came easier that time, warm and immediate.

But Fabian, sensing blood, leaned over the table and said, “No, no, no. Real embarrassment. Something scandalous.”

“Yes,” Barty purred from the Slytherin side. “Do keep up, Lupin.”

Remus looked actively miserable now.

And that only made everyone lean closer.

Frank rested his chin on his hand. “All right. Have you ever fancied someone in this room?”

Dead silence.

James slowly turned.

Sirius slowly turned.

Peter made a strangled little noise.

Remus said, with the doomed calm of a man watching his own execution, “Yes.”

The dungeon detonated.

“No way!”

“Who?”

“Tell us!”

“Holy shit—”

Slughorn half-heartedly raised a hand. “One at a time, one at a time—”

“Who is it?” Sirius demanded immediately, standing.

Remus did not answer.

Because he did not have to.

Because every eye in the room had already found somewhere to land.

Somewhere dark-haired and composed and sitting very still at the Slytherin table.

Regulus, to his enormous credit, did not visibly react for a full two seconds.

Then Barty made the softest, most delighted sound anyone had ever heard.

“Oh,” he said.

Pandora slapped a hand over her mouth.

Dorcas turned so sharply to stare at Regulus it was a wonder she didn’t wrench her neck.

Evan’s brows lifted by a fraction.

James looked between Remus and Regulus like he’d just been handed the meaning of life.

Sirius, meanwhile, went through six separate emotions in the span of one breath—shock, disbelief, offence, delight, outrage, and something perilously close to hysterical joy.

“You,” Sirius said to Remus, voice cracking, “have a crush on Regulus?”

Remus stared at the ceiling. “Yes.”

The screaming started.

Actual screaming.

Marlene slammed both palms on the desk. Mary was doubled over. Fabian had fallen sideways into Gideon. Alice was choking on her own laughter while Frank thumped her back uselessly because he could not stop laughing either. Peter had both hands over his face. James was making wild, incoherent gestures at absolutely everyone.

Sirius looked ready to ascend.

“My brother?” he cried. “My baby brother? My horrible little snake of a brother?”

“Do not call me that in public,” Regulus said coldly, finally speaking.

That only made it worse.

“Remus,” James gasped, gripping the edge of the desk for support, “since when?”

Remus swallowed. “A while.”

“A while how long?” Lily asked, eyes alight.

“Since last year.”

Pandora made a shriek so sharp it could have cut glass.

Barty clapped once, delighted. “This is the best day of my life.”

Slughorn was openly fascinated now. “Well, Mr Lupin, perhaps you ought to be more specific.”

Remus laughed once, hollow and humourless. “You are all evil.”

“Specific,” the room chanted.

“Specific.”

“Specific!”

Remus squeezed his eyes shut.

Then opened them.

And because the potion would not let him stop, because there was no refuge left, because every secret he’d carefully kept folded away was now being pried open in front of half the school—

He said, hoarsely, “It’s not just a crush.”

Another stunned beat.

Then James, very softly, “Oh, no.”

Remus kept going.

“It’s worse than that.”

Sirius put both hands over his mouth.

Remus spoke like every word physically pained him. “I’m a little obsessed with him.”

The class erupted again.

Regulus went utterly motionless.

Barty had stopped laughing now—not because he wasn’t entertained, but because this had become too interesting to interrupt.

“What do you mean,” Dorcas said, with terrible calm, “a little obsessed?”

Remus dragged a hand over his face. “I mean exactly what it sounds like.”

“No, no,” Mary said, almost breathless. “Explain.”

“Please,” Marlene begged.

“Expound,” Gideon said grandly.

Fabian pointed dramatically. “Tell the court everything.”

Remus groaned like a man in active prayer for death. “I notice him all the time.”

Regulus’s gaze was on him now.

Not amused.

Not flustered.

Just fixed, unreadable, dark and sharp as a blade left in velvet.

It was somehow worse than if he’d looked angry.

Remus swallowed and kept talking.

“I know when he’s in a room even if I’m not looking at him first. I know the sound of his footsteps in the corridor. I know when he’s had a bad day because he goes quieter than usual. I know when he’s irritated because the left side of his mouth twitches. I know he acts like he doesn’t care what anyone thinks, but he always tightens his grip on his books when people stare too long.”

The room had gone quieter now—not silent, not with this many people packed into one dungeon, but quieter. The laughter was still there, but softened by attention.

Even Slughorn did not interrupt.

Remus let out a shaky breath. “I know he wears baggy clothes all the time, and I know that makes most people underestimate him.”

Regulus’s expression flickered.

Only once.

Sirius lowered his hands from his face. James stared at Remus like he’d never seen him before in his life.

And because fate was cruel, because truth was crueler, Mary said gently, “What happened?”

Remus looked at her. “What?”

“You said you know he wears baggy clothes. You said most people don’t know what he looks like. So what happened?”

The dungeon leaned in as one.

Even the potion bubbling in the cauldrons seemed quieter.

Remus’s ears went red.

Slowly. Visibly.

“Oh, hell,” Sirius whispered.

Remus laughed once without joy. “It was an accident.”

Pandora made the tiniest delighted gasp.

“What was?” James asked.

Remus did not answer.

So Barty did.

“The seeing,” he said, smiling like a knife.

Remus looked like he wanted the floor to split open and claim him.

“It was an accident,” he repeated.

“Remus,” Lily said, voice dangerously calm, “what did you see?”

He stared at her in mute despair.

Then, because the potion held him by the throat, he said it.

“I saw his waist.”

The noise that left the class barely qualified as human.

Sirius folded over the desk like he’d been shot.

James shrieked.

Peter made a wheezing sound so violent Frank had to steady him.

Marlene actually slapped the tabletop hard enough to rattle everyone’s ingredients.

Regulus did not move.

Not a muscle.

But Evan turned to look at him now with a kind of slow, sidelong interest, as though the next five minutes promised to be extremely worth living through.

Remus was bright red.

“It was an accident,” he said again, absolutely to no one’s sympathy. “I walked into the hospital wing one evening because Madam Pomfrey had asked me to drop off a book, and the curtain around one of the beds wasn’t fully shut, and he was there, and he was changing his shirt, and I only looked for a second—”

“A second?” Fabian repeated.

Remus’s eyes closed. “Fine. Longer than a second.”

Laughter burst again.

James was openly crying now. “Moony, no.”

Remus ignored him with the bravery of the truly damned. “He always wears oversized jumpers, or robes, or layers, and I had never— I mean, I knew he was slim, obviously, but I had never actually seen—”

He broke off, swallowed, then forced himself onward.

“His stomach.”

Regulus’s fingers tightened around the stem of his spoon.

“His waist.”

A stunned little hush.

Remus’s voice got lower. Rougher.

“Small. Slim. Properly cinched.”

Nobody breathed.

“He had these sharp hip bones,” Remus said, staring at the floor now as if it might still save him, “and long legs, and I could see the line of him properly for the first time and I have literally not stopped thinking about it since.”

The dungeon went mad.

People were shouting over each other now, half scandalised, half ecstatic.

“Merlin above—”

“He said hip bones—”

“Remus!”

“You are finished!”

Sirius was laughing so hard he could barely remain upright. “My God. My God. You’re foul.”

James had both hands on his head. “This is unbelievable. This is transcendent. This is the best thing that has ever happened to me.”

Mary was gasping for air. Marlene was pounding her fist on the desk in a broken rhythm. Alice had tears streaming down her face. Frank was fully red with it. Fabian and Gideon looked like they wanted this moment preserved in stained glass.

At the Slytherin table, Pandora had her face buried in her arms, shoulders shaking. Dorcas was staring between Remus and Regulus with naked fascination. Barty looked lit from within.

Evan alone looked almost thoughtful.

Regulus sat perfectly straight.

Too straight.

His face unreadable.

His ears, however, had gone the faintest shade pink.

Remus, to his horror, kept speaking.

“It was like a religious experience.”

That did it.

The room dissolved again.

James was folded in half.

Sirius clutched at his own throat, choking on laughter.

“Religious?” Peter squeaked.

Remus covered his face with one hand. “Yes.”

“Explain,” Barty said immediately.

Remus dropped his hand and glared at him with tragic fury. “It was awful.”

“That is not an explanation,” Dorcas said.

“It felt,” Remus said through gritted teeth, “like God himself had singled me out for torment.”

Pandora hit the desk with both palms and howled.

Remus forged on, because he had no choice, because every instinct to stop was now irrelevant. “I saw that waist for maybe ten seconds, and it has haunted me ever since. Absolute nirvana. Horrific. I’ve been miserable for months.”

Sirius had gone silent with laughter again, which was somehow more unhinged than the noise.

James clutched at his shoulder. “Moony, mate—”

“No, let him finish,” said Marlene instantly.

“Oh, definitely let him finish,” said Fabian.

“Hands down,” Gideon agreed.

Lily, trying and failing to sound stern, said, “Remus. How bad is it?”

Remus looked at her.

Then said, with quiet devastation, “Very bad.”

“How bad?” Mary pressed.

He hesitated.

Then the potion yanked the truth out of him anyway.

“I think about grabbing him by the waist more often than is probably healthy.”

There was a split second of silence.

Then every single person in the room lost their mind.

Regulus blinked once.

Slowly.

Sirius physically sat down on the floor.

James had gone fully boneless against the desk.

Peter made the sign of the cross for reasons known only to him.

“What do you mean, grabbing him by the waist?” Frank demanded, half-laughing, half-yelling.

Remus’s whole face burned. “Exactly what it sounds like.”

“Remus,” Alice said, wiping at her eyes, “for the love of God.”

“I just—” He stopped, jaw tightening. “Every time I see him, I have the most deranged urge to put my hands there and pull him closer.”

The class made a collective sound somewhere between scandal and worship.

“Because he’s small,” Remus said helplessly, furious at himself, furious at the potion, furious at the room. “And I’m not.”

James stared. “That’s your reasoning?”

“It’s part of it!”

Pandora’s laugh came out strangled and bright.

Remus looked like he wished he’d died in infancy. “He’s just— he’s built in a way that makes me insane.”

Barty slowly put a hand over his heart. “What poetry.”

“Shut up,” Remus snapped.

“You can’t tell me to shut up while drugged into honesty,” Barty said cheerfully. “This is not how tyranny works.”

Slughorn, who really should have intervened by now and plainly had no intention of doing so, polished his spectacles and asked, “Would you care to elaborate on ‘built in a way that makes me insane,’ Mr Lupin?”

Remus turned to stare at him with naked betrayal. “Professor.”

Slughorn smiled blandly. “For the integrity of the demonstration.”

“You are a terrible educator.”

“Nevertheless?”

Remus made a noise deep in his throat and looked back out at the class.

At James, already dying.

At Sirius, flat on the floor and weeping with joy.

At Lily, who had given up all pretence of control.

At the Gryffindors, openly feral.

At the Slytherins, no better.

At Regulus—

Who was still watching him.

Still not looking away.

Remus’s voice went rougher.

“His whole frame is unfair.”

Nobody moved.

“He’s all sharp lines until he isn’t. Slim shoulders. Narrow waist. Long legs. He looks delicate until he doesn’t, and then you realise there’s something mean in the way he carries himself, and that makes it worse.”

The dungeon was a live wire.

Remus was no longer even speaking quickly now. He sounded resigned. Doomed. Like he knew he’d be replaying this humiliation for the rest of his natural life and had accepted it with bleak dignity.

“And yes,” he said, staring at a crack in the stone wall behind the Slytherin table, “I think about biting him sometimes.”

The class erupted so violently that one of the Ravenclaw girls at the back nearly fell off her stool.

Sirius let out a laugh so loud it echoed.

James was pounding the table now.

Peter had stopped pretending he was embarrassed for Remus and was fully enjoying himself.

Dorcas looked like Christmas had come early.

Pandora made a shocked little noise into both hands.

Evan finally smiled, small and sharp.

Regulus’s expression did not change.

Not much.

But one eyebrow lifted.

Just slightly.

And Remus saw it.

Which, tragically, made everything worse.

“Not in a murderous way,” Remus said at once, as though that helped. “In a—”

“In a what?” Fabian yelled.

“In a yearning way!” Remus shouted back, scandalised.

The roar of laughter was almost enough to shake dust from the ceiling.

James had collapsed into Lily’s shoulder. Even she had tears in her eyes now. Frank was bent over, clutching his ribs. Alice was trying and failing to breathe normally. Mary and Marlene looked half a second from full possession.

“Yearning,” Gideon repeated faintly.

“Oh, he is finished,” Marlene gasped.

Barty, with all the delighted evil in him, leaned forward on his elbows and asked the question that should never, under any circumstances, have been asked.

“What do you dream about?”

Remus froze.

The room froze with him.

Even James stopped laughing.

Because they all knew.

All of them.

They all knew this was going to be catastrophic.

“Don’t,” Remus said.

“I think,” Barty said softly, “that is an answer in itself.”

Pandora stared at Remus in horrified fascination. Sirius had risen halfway off the floor, hand over his heart, face lit with the kind of terrible joy only siblings could feel at each other’s ruin.

“Remus,” James whispered, reverent with dread.

Lily looked like she wanted to stop this and also absolutely did not want to stop this.

Regulus, for the first time all lesson, looked the faintest bit tense.

Remus’s hands clenched.

Then unclenched.

And the potion dragged him under.

“I have had dreams about him,” he said.

The class made a sound like a chapel full of sinners.

Remus stared fixedly ahead. “At night.”

Sirius shut his eyes and whispered, “No.”

“Yes,” said Remus miserably.

Mary pressed both hands to her cheeks. “Oh my God.”

Remus said, because the truth was merciless, “They are not innocent dreams.”

Absolute bedlam.

James shouted something incomprehensible. Peter actually stood up and then sat back down again because he had nowhere to put the energy. Fabian nearly throttled Gideon by accident in his excitement. Marlene was openly shrieking. Alice fell against Frank’s shoulder. Slughorn’s eyes gleamed with awful scholarly interest.

And across the room, Regulus was no longer pink at the ears.

He had gone properly, visibly flushed.

Only a little.

Only if one was looking.

But he had.

Remus looked like he wished a meteor would hit the dungeon.

Barty, because he was a menace upon the earth, asked sweetly, “About what, exactly?”

Remus laughed, once, in despair. “You know exactly about what.”

“Say it,” Pandora whispered.

Dorcas elbowed her without even looking away from the front.

Remus dragged a hand down his face. “About touching him. Pulling him close. Kissing him until he stops looking so composed.”

A wave of sound rolled through the room.

Sirius’s mouth fell open. “Remus John Lupin.”

James pointed a trembling finger at him. “You filthy liar. You’ve been secretly the worst of us this entire time.”

“That is untrue,” said Sirius.

“No, actually, I think it’s true,” said Lily.

Remus was beyond shame now. There was something almost eerie about it—the way embarrassment had peaked so violently it had become a strange, calm kind of ruin.

“And yes,” he said, voice hoarse, “sometimes when he walks past me, all I can think about is grabbing him by the waist and pulling him back.”

The room screamed again.

Regulus finally looked away.

Only for a second.

Only down at his desk.

But it happened.

And Evan noticed.

Barty noticed.

Pandora noticed.

Dorcas absolutely noticed.

So did Sirius, whose eyes widened with the speed of revelation.

“Oh, my God,” he said.

James turned. “What?”

Sirius was staring at his brother with religious intensity. “Nothing.”

Which, from Sirius Black, meant absolutely everything.

But before anyone could pin that down, Fabian shouted, “What else?”

“Yes!” Mary said. “More!”

“Enough,” Remus groaned.

“Absolutely not enough,” Marlene replied.

Alice raised a hand like this was still somehow civilised. “You said you think about his waist. Fine. You said his whole frame is unfair. Fine. Is there anything else?”

Remus should have lied.

He couldn’t.

He exhaled through his teeth and said, “His arse.”

For one stunned, glorious heartbeat, the room was silent.

Then the dungeon ceased to function as a learning environment entirely.

Sirius made a noise no human had ever made before.

James physically slid off the edge of the desk.

Peter clapped both hands over his face and bent double.

Lily was laughing too hard to even protest the word choice.

Frank slapped the table. Alice wheezed helplessly against him. Gideon fell into Fabian. Mary and Marlene were all but shrieking.

Pandora had simply given up and was lying flat across her table.

Barty was glowing.

Remus looked like a saint in a martyr painting.

“He has a cute arse,” he said into the chaos, because of course he did, because apparently his suffering was not yet complete.

Regulus went rigid.

“He’s tiny,” Remus said with sickening sincerity. “I know I could fit my whole hand over one cheek.”

The class lost every remaining shred of sanity.

Slughorn took one step back from the force of it.

Sirius sat on the floor again.

James was making helpless grabbing motions at the air.

“No,” Peter cried. “No, I can’t do this.”

“Yes, you can,” Barty said, laughing. “And you will.”

Remus kept speaking, inexorable, unstoppable, the truth pouring out of him like blood from a wound.

“It’s the fact that he’s small and I’m bigger than him that makes it worse.”

“Oh, he said it again—”

“He said bigger—”

“Merlin save us—”

Remus’s voice cracked with fury. “It’s not my fault that’s hot.”

The response to that was pure anarchy.

Even Slughorn laughed outright.

Even some of the quieter students at the edges of the room, who hadn’t said a word all lesson, were now openly in hysterics.

And in the middle of it—at the very center of that storm—Regulus Black sat very still indeed, face composed with murderous effort, ears red, throat slightly flushed, eyes lowered to his notes as though he could will himself somewhere else by sheer concentration.

It did not work.

Because Sirius saw everything.

Sirius always saw everything about Regulus.

And a slow, wicked grin began to spread over his face.

“Oh,” he murmured.

James looked at him blearily through tears. “What?”

Sirius stood up.

Straightened his robes.

Turned.

And in a voice of pure brotherly menace, asked, “Regulus.”

The room snapped quiet at once.

Because this was new now.

This was dangerous.

Regulus lifted his gaze. “Don’t.”

“Do you,” Sirius said, smiling like the devil himself, “have any thoughts on this?”

Regulus stared at him.

At Remus.

At the entire room waiting like held breath.

And said, icy and precise, “Yes.”

The class leaned so far forward it was a miracle nobody toppled.

Sirius’s grin widened. “Go on.”

“No.”

“Coward.”

Regulus’s eyes narrowed. “Keep speaking and I’ll poison you in your sleep.”

“See?” James whispered to Remus in delight. “He does like you. That was practically flirting.”

“It was a threat,” Lily said.

“With chemistry,” James argued.

“With homicide,” Dorcas corrected.

Remus had gone so red he might actually combust.

But Sirius wasn’t done. Of course he wasn’t.

He folded his arms. “Do you object to being admired, little brother?”

Regulus’s mouth tightened.

Then, after one long second, he said, “I object to hearing about it in Potions.”

A fresh wave of chaos crashed over the room.

James shouted, “That’s not a no!”

Pandora sat up so fast she nearly knocked over her ink. “It is literally not a no!”

Barty pressed a hand to his chest again. “I’m going to frame this day.”

Evan, at last, spoke from where he lounged beside Regulus, voice smooth with amusement. “You’re blushing.”

Regulus turned to him with killing intent. “Die.”

“That’s a yes,” Barty sang.

“It is not.”

Dorcas, chin in her hand, looked Regulus over with maddening calm. “You’re not leaving.”

Regulus said nothing.

Which was the worst possible thing he could have done.

Because now everyone saw it.

The way he stayed seated.

The way he did not tell Remus to shut up.

The way his expression was controlled, yes, but not disgusted.

Not angry.

Just… shaken.

Interested, maybe.

Only maybe.

But maybe was enough to kill a room like this dead and then bring it roaring back to life.

Remus looked like he might pass out.

Sirius put both hands on his hips, glowing with infernal satisfaction. “This is better than Christmas.”

“You don’t even like Christmas,” Regulus said.

“I do now.”

Slughorn finally cleared his throat, though he sounded like a man reluctant to end a masterpiece. “Well. This has certainly been illuminating.”

“That is one word for it,” Lily muttered.

“I think,” Slughorn continued, moustache twitching, “we have perhaps extracted all the educational value possible from Mr Lupin’s current condition.”

“No!” half the class shouted immediately.

“Yes,” said Remus.

Slughorn ignored them both. “Five points to Gryffindor for… participation.”

“Only five?” James cried. “Professor, we’ve given you theatre.”

“You’ve given me a headache.”

He waved his wand, Summoned a goblet of water, and handed it to Remus, who drank it like a man trying to drown himself from the inside out.

The class was still buzzing, still laughing, still turning to one another in breathless disbelief.

Snatches of it broke loose all over the room.

“Did you hear him say hip bones—”

“Whole hand—”

“Yearning way—”

“Religious experience—”

“Not innocent dreams—”

Remus made a sound of profound, exhausted suffering and dropped his forehead onto the edge of Slughorn’s desk.

James strode up immediately and draped himself over Remus’s back. “Mate,” he said, voice wobbling with suppressed laughter, “I need you to know that I will never let this go.”

Sirius joined him a second later. “Never. Ever.”

Peter appeared at Remus’s side and patted his arm. “I’m so sorry.”

“You’re smiling,” Remus said into the wood.

“I’m trying not to.”

“You’re failing.”

“Yes.”

When Remus finally lifted his head, he made the mistake of glancing across the room.

Straight at Regulus.

For half a second, everything else dimmed.

The noise, the laughter, the scraping stools, the hiss of potions over flame.

Just that look.

Regulus met his eyes.

And this time he did not look away first.

His face was still controlled. Still cool. Still impossible.

But there was colour in it now.

And something else.

Something sharp and unreadable and almost—almost—curious.

Then Barty leaned in to say something in his ear, Pandora hissed at Dorcas, James started laughing again beside him, Sirius was already plotting six months of psychological warfare, and the moment broke apart into noise.

But it had happened.

Remus had seen it.

And judging by the expression on Sirius’s face, so had he.

Slughorn clapped his hands sharply. “Back to your seats, all of you. If even one of these cauldrons is ruined while you gossip, I shall assign three feet of parchment on the ethics of veracity potions.”

There was a general groan.

Stools scraped.

Students rose.

The lesson attempted, bravely and without much hope, to become a lesson again.

Remus walked back to the Gryffindor table like a condemned man.

James was grinning so hard it looked painful.

Peter would not stop making tiny distressed noises every time their eyes met.

Sirius looked like he had swallowed the sun.

“I hate you all,” Remus said, sitting down heavily.

James clapped him on the shoulder. “Counterpoint: this is the greatest day in academic history.”

“I’m transferring schools,” Remus muttered.

“You can’t,” Sirius said. “You’re spiritually chained to this dungeon now.”

Peter leaned closer. “For what it’s worth, I didn’t know.”

“None of you knew,” Remus said bitterly.

James winced. “That part, admittedly, is true.”

Sirius propped his chin on one hand and looked far, far too delighted. “You do realise, obviously, that I’m going to watch both of you like a hawk now.”

“Please don’t say ‘both of you’ like that,” Remus said.

“Oh, no. Absolutely both of you.”

“Nothing happened,” Remus hissed.

Sirius arched a brow. “Nothing happened yet.”

Remus closed his eyes in pain.

At the Slytherin table, Barty was still talking. Pandora was still cackling softly every few seconds. Dorcas kept glancing between Regulus and the Gryffindor side with the open interest of someone following a particularly juicy serial. Evan had that same unreadable little smile still playing at the corner of his mouth.

And Regulus—

Regulus had gone back to his potion.

Mostly.

His hands were steady now.

His face composed.

But every now and then, against his will or perhaps because of it, his gaze flicked once—only once—toward the opposite side of the room.

Toward Remus.

And every single time, Sirius noticed.

So did James.

Eventually Lily did too, and then Mary, and then Marlene, and then Fabian and Gideon, and once that happened, the knowledge spread through the room like spilled ink.

Nobody said anything outright.

Not yet.

But the air had changed.

Potions resumed.

Quills scratched.

Flames hissed.

The silver draft in the cauldrons thickened and darkened by degrees.

And beneath all of that, something else simmered too—something meaner, sweeter, more dangerous.

The aftermath.

The talk that would follow in corridors and common rooms.

The weeks of merciless torment Remus would endure.

The weapons Sirius would fashion from every single word spoken today.

The way Barty would absolutely tell this story again with added dramatics.

The way Pandora would start saying “religious experience” at inappropriate moments for the rest of the year.

The way James would bring up “yearning way” until one of them died.

And underneath even that—

The quieter thing.

The look across the room.

The fact that Regulus Black had not denied anything that mattered.

Remus sat very still at his desk and stirred the potion far longer than necessary.

Beside him, Sirius leaned in and whispered, bright with wicked delight, “So. My brother’s waist, hm?”

Remus put his face in his hands.

James nearly choked laughing.

Across the dungeon, without looking up from his cauldron, Regulus said coolly, “If either of you says the word waist again, I’ll hex your tongues together.”

Sirius threw his head back and laughed.