tension theory/friction principle bonus chapter
set a month before the events of friction principle and a month after the events of tension theory.
The apartment is dim. A lamp glows in the corner of the living room, throwing soft gold over the chaos, solo cups, empty beer bottles, crumpled napkins. The tell tale signs of 'boys night' at Heeseung's apartment.
Sunghoon's on the couch, head tipped back, legs sprawled wide. His lips are parted slightly, a little flushed. His hair falls over his eyes, his phone clutched loosely in one hand—screen dark. He hasn't looked at it in fifteen minutes. Your last text is burned into his memory anyway.
You: go have fun, i don't wanna be at bOys nIghT😂
He sighs. Drunk, but not mindless. Slowed, but aware.
And all alone, Jake long gone goofing around somewhere with Jungwon.
There's movement to his left. He doesn't open his eyes at first. He assumes it's Heeseung coming back out, that's until he smells perfume. Not the kind he likes, this one's heavier and manufactured sweet.
"Rough night?" Yunjin's voice lilts, playful and syrupy. She plops down next to him without invitation, knees brushing his. "You've barely said a word all night."
"M'fine," he mumbles, voice thick.
"You don't look fine." Her fingers curl over the back of the couch behind him, close to his shoulder.
Sunghoon opens his eyes slowly. She's staring at him, her mouth curled into something that could pass as a smile if it weren't for the sharpness behind it.
"You miss your little girlfriend?" she asks, tilting her head. "You look like a kicked puppy."
He straightens slightly. "Why are you even here?"
"Mm." Yunjin lets the syllable hang. "Don't you get tired of it?"
He frowns. "What?"
"Pretending that's what you want. The innocence. The slowness. You could have so much more, you know."
"Plus I know her. And she's definitely not giving it up. Or is she?"
His face hardens a little, but his body stays relaxed — maybe too relaxed to react properly. "She's exactly what I want."
She laughs. "Sure. For now."
Sunghoon doesn't answer. She leans in anyway, closing the space like she hasn't said anything wrong.
"You know Heeseung's out cold," she says softly. "And she's not here. Nobody's here. You don't have to pretend."
Her hand drops to his thigh—barely above his knee; like she's testing him.
Sunghoon shifts, his leg jerking slightly to the side. "Stop."
But she doesn't. She leans in closer, so her breath grazes his jaw. "I won't tell. Heeseung doesn't have to know."
"Yunjin." His tone is sharper now, his brow furrowed.
She swings a leg over him in one practiced move, suddenly straddling him. Her hands are on his chest, pushing under his jacket, nails trailing. "C'mon, Sunghoon," she whispers, hovering over him to perch on his thighs—straddling him.
Her hands ghost over his chest, nails trailing down, inching lower. She adjusts her position, shifting her weight deliberately as she presses her hips against him.
But there's nothing, no response. No sharp inhale, no movement, no tension in his jaw. Just an empty daze in his half-lidded eyes. His body doesn't stir under her touch—doesn't respond at all.
Still, she keeps going. More pressure. Bolder now. She leans down, pressing her lips to his neck, letting them drag over his skin, hands moving to his waistband with intent.
But there's nothing to work with.
He's soft. His body unresponsive, untouched by the friction or the proximity. It's not arousal—it's absence. A deadweight of intoxication or the fact that his body simply isn't moved by her—keeping him utterly unreachable.
She tries again, more insistent this time, and he groans—not with pleasure, but with discomfort. A sluggish frown creases his brows. His hands attempt to push her away, slow and loose, like his limbs aren't listening.
"What the fuck are you doing?"
Door flung open. Jake's voice through the silence like a crack of thunder.
Yunjin flinches. Sunghoon's head lolls sideways toward the sound, lips moving around Jake's name like a lifeline.
Jake doesn't wait. He crosses the room in three long strides and yanks her back, eyes blazing.
"You fucking psycho." "Get off him," he says, voice low, livid.
"He didn't say no—"
"He's drunk, you freak," Jake snarls, stepping in front of Sunghoon. "Get the fuck out."
Yunjin looks between them—defiant, defensive—but Jake's already pointing at the door.
"Now."
She storms out in a flurry of sharp perfume and sharper heels, slamming the door hard enough to rattle the frame. The air crackles in her absence, heavy with tension that only breaks when Jake exhales, dragging a hand down his face.
Sunghoon's still draped across the couch, boneless and blinking slowly like he's just registered Jake's presence for the first time. His head lolls toward him, a lazy grin spreading across his flushed face.
"Jakeee," he hums, reaching out with both arms.
Jake sighs but crouches again anyway, pulling Sunghoon up with practiced care, steadying the taller boy's weight against his chest. He smells like whiskey and cologne.
"You're so annoying when you're drunk," Jake mutters, wrapping an arm around his waist.
But Sunghoon just laughs, soft and breathy, pressing his face into the crook of Jake's neck. His lips brush there once, twice, then again with more intention. Not quite kisses, more like lazy nuzzles. Familiar, intimate and even possessive in a slow, syrupy way.
He mouths at Jake's jaw, then down his throat, mouthing a warm stripe over his collarbone. His hands slide beneath Jake's shirt, cold fingers against warm skin, touching aimlessly at first...but then one trails lower, settling with a firmer kind of intent.
Jake flinches.
He looks down, eyes widening slightly when he feels the change in Sunghoon's body against his thigh—the sudden tension, the unmistakable press of Sunghoon’s hardened cock.
"Seriously?" Jake breathes out, somewhere between disbelief and concern.
But Sunghoon's not listening. He shifts, trying to pull Jake closer, sliding one of Jake's hands down between their bodies. Not guiding or forcing—just placing it there.
Jake swears under his breath, heart pounding harder now. Not because of what's happening, but because of what it means.
Sunghoon, drunk off his ass, completely unresponsive to someone else. But here, clinging to Jake like gravity itself depends on it, completely undone by the sound of his voice and the heat of his hands.
Jake looks at him, lips parted, stunned. And Sunghoon, eyes half-lidded and glassy, just presses another kiss to Jake's cheek and mumbles something soft; your name, like a prayer.
Sunghoon looks down, suddenly serious. "Don't tell her, okay?"
"I won't," Jake whispers.
And then Sunghoon kisses him. A soft, slightly sloppy press of lips—nothing filthy, nothing practiced. Just raw, messy and needy.
Jake blinks, a little stunned.
"Such a clingy drunk," he says softly, brushing a hand through Sunghoon's hair.
"I love her," Sunghoon murmurs again. "And you too."
Jake smiles faintly. "Yeah. I know."
And he lets him hold on, before guiding him out of Heeseung’s apartment.
The door clicks open. Jake's arm is looped around Sunghoon's waist, half-dragging, half-guiding him in through the entryway.
Sunghoon's still a mess in the most uncharacteristic way, cheeks flushed, hair mussed, black shirt rumpled where Jake's been gripping him. He stumbles once on the carpet and just laughs.
"I'm fiiine," he insists, drawling out the word like it's an inside joke.
Jake snorts. "You're not fine. You shouldn’t have drank five of Heeseung's jungle juice monstrosities."
Sunghoon grins. "They were sooooo good."
Jake doesn't respond. He's too busy trying to keep Sunghoon upright, nudging open Sunghoon’s bedroom door with his foot.
"Hi," your voice rings out, soft and bright.
You're fresh out of the shower, towel wrapped snug around your body, damp hair tucked behind your ears. You're standing by the dresser, lotion half-rubbed into your arm, blinking at the two of them like you weren't expecting company.
Sunghoon stops dead in the doorway. His eyes go wide.
"Oooooooouuuuuu," he howls, dragging the word out like a cartoon character. "Y/N in her towelllll."
Jake closes his eyes. "Here we go."
Sunghoon wiggles out of Jake's grasp, swaying a little as he stumbles toward you with all the awe of a man witnessing a miracle.
"Wait—no wait," he slurs, grinning crookedly. "Hold on. You look like a dreeeeam."
"Sunghoon," you say carefully, lips quirking, "how much did you drink?"
"A lot," Jake says at the same time that Sunghoon points at you dramatically. "Not enough."
You giggle, surprised and delighted by how silly he's being. You've never seen him like this—all loose limbs and rosy cheeks, his usual sharp edges melted down to something warm and dopey.
"C'mere," he says, reaching for you. "Let's take this off."
And then his fingers find the knot of your towel.
"Hoon!" you squeal, laughing as you stumble back and hold the towel tighter, but he’s determined.
You squeal again, backing up more. "Hey—wait—!"
But he's already undoing it, and the towel slips to the floor with a whisper, leaving you bare and blinking up at him, caught somewhere between shock and laughter.
"Oh my God," you whisper, face heating. "You actually—!"
Sunghoon hums like he's reached nirvana. "So soft," he marvels, hands coming up to cradle your waist, skimming over your arms and shoulders, then back down to your hips.
You're still laughing, heart thudding a little too fast. Sunghoon turns in Jake's arms, swaying again.
"I didn't let them," he mumbles suddenly.
Jake freezes.
"What?" you ask gently.
Sunghoon doesn't look at you. He's looking at the floor now, fingers twitching at the hem of his shirt.
"There were people...at the party. Someone tried to...y'know. Touch me. But I didn't let them." He whispers the last part like a little secret.
Your smile slips just a bit.
Jake cuts in quickly, tugging Sunghoon toward the bed. "He's exaggerating. It's fine now. He just got overwhelmed, that's all."
But you're already walking over, placing a soft hand on Sunghoon's cheek. His eyes flutter closed at the touch like he's been starved for it all night.
"You okay?" you whisper.
He nods. "Now that you're here."
And then, like the switch never flipped, he perks back up. "Wait—can you do that lotion thing again? You smell like vanilla clouds."
Jake groans, letting his head fall back against the wall.
“I’m gonna get him to bed.”
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a/n: more bonus chapters to come cause we call can’t let this story go yet 🤧
















