𐙚 My biggest mistake𐙚

Natasha Romanoff x reader

a/n : this is gonna be a series cause i said so 🤓

if your on this taglist and don’t want to be anymore just let me know and you’ll be removed and if your not on here and want to be added just let me know also!

@24kbils @fein4lararaj @marieilish1823 @emiliesblohsh @bitchesbrokenpromises @urfavvbilliemunch @billieshostage

The training room smelled like sweat, steel, and ozone from the static charge that always clung to the walls whenever Thor trained there. Most days, Y/N loved that smell. It meant safety. It meant she’d survive another mission to come home to him.

But Thor wasn’t here today.

Today was Natasha.

And Natasha trained differently—quiet, predatory, analyzing the shape of Y/N’s breathing before Y/N even knew she was winded. It wasn’t romantic, and it wasn’t friendly. It was… something else.

“Again,” Natasha ordered.

Y/N barely had time to reset her stance before Natasha swept her leg out. Y/N dodged by inches, heart punching against her ribs.

“You’re slow today,” Natasha said, circling. “Distracted.”

“I’m not distracted,” Y/N lied.

“You’re dating a god. You think he can’t feel when something’s off with you?”

Y/N swallowed hard. Natasha was far too good at reading people. It was part of the job—but with Natasha, everything always felt personal. And today, she was standing too close. Breathing too close.

“I’m fine,” Y/N repeated.

Natasha didn’t look convinced.

She lunged first, taking Y/N down in one brutal, fluid movement. Y/N hit the mat with a grunt, breath knocked out. Natasha stayed hovering over her, one knee between Y/N’s legs, the other pressed into the mat for leverage.

They froze.

Natasha’s hair fell forward, a curtain of red that brushed Y/N’s cheek. Her breath hit Y/N’s jaw.

Too close.

Way too close.

“Tell me you’re not distracted,” Natasha whispered.

Y/N couldn’t.

Natasha’s eyes flicked to her mouth.

And that was the first moment the tension broke—into something far more dangerous

Natasha pushed off of Y/N and stood up like nothing happened, but her jaw tightened. “Again.”

Y/N got to her feet. She wasn’t steady.

Natasha came at her harder.

This time Y/N blocked, countered, grabbed Natasha’s wrist, pulled—

But Natasha reversed it instantly, slamming Y/N back against the wall. Her hand locked around Y/N’s wrist, pinning it above her head. Her other hand pressed against Y/N’s hip.

Y/N gasped—not in pain.

And Natasha heard it.

Her eyes darkened in a way that had nothing to do with battle.

“Careful,” Natasha murmured. “You’re making noises you shouldn’t be making with me.”

Y/N’s body betrayed her entirely—leaning in, seeking heat that wasn’t hers to seek.

Natasha’s breath hit her ear. “You don’t get to look at me like that when you go home to someone else.”

“I wasn’t—” Y/N began.

“Yes, you were.”

Natasha backed up half an inch.

Half an inch was too much. Y/N grabbed her wrist, pulling her back in without thinking.

And that was it.

Natasha’s mouth crashed into hers.

The kiss wasn’t soft. It wasn’t hesitant. It wasn’t careful. It was violent in its urgency, teeth, heat, adrenaline.

Natasha dragged Y/N backward until Y/N hit the mat again, Nat climbing over her, kissing like she needed air and Y/N was the only source. Y/N kissed back—hungry, reckless, in a way she never had with Thor.

Her hands found Natasha’s waist.

Natasha groaned, low and dangerous.

She shifted her weight, straddling Y/N’s hips as their mouths moved like they’d been waiting for this for years instead of seconds.

“Nat—” Y/N whispered against her lips.

“Don’t say my name like that,” Natasha breathed, kissing her harder. “Not unless you mean it.”

Y/N did. God, she did.

Natasha’s hand slid under Y/N’s shirt, up her stomach, fingertips skating across skin that shouldn’t have been hers to touch.

Y/N arched.

Natasha cursed under her breath.

Y/N gasped as if waking from a dream.

Natasha had already pulled back—breathing hard, flushed, pupils blown wide with regret and desire tangled into one.

“What did we just do?” Y/N whispered.

Natasha didn’t answer. She stood up, running both hands through her hair, pacing once like she was trying to outrun her own pulse.

“We shouldn’t have done that,” Natasha said under her breath.

Y/N pushed herself upright. The world was spinning. Her lips were swollen. Her body still hummed with a fire that wasn’t Thor’s, had nothing to do with him.

“I didn’t mean for—” Y/N began.

“Yes, you did.” Natasha’s voice cracked, barely audible. “And so did I.”

That made it worse.

Y/N’s chest tightened. “I love Thor.”

Natasha flinched. “You say it. You don’t feel it right now.”

“That’s not fair.”

“No,” Natasha said quietly. “It’s not. Nothing about this is fair.”

Silence pulsed between them.

Natasha turned away. “You need to go before I make this worse.”

The problem was—Y/N didn’t move.

Because walking away from Natasha felt like trying to walk off a cliff.

Thor found Y/N in their room later, sitting on the edge of the bed like someone who’d forgotten how to breathe.

He immediately frowned. “Y/N? Something troubles you.”

His voice was soft—too soft. Closer to a worried lover than a god.

Y/N’s throat closed.

Thor sat next to her, sliding one massive hand over hers. His warmth was familiar. Safe. Good.

And it made her stomach twist with guilt so hard she thought she’d be sick.

He studied her face. Slowly. Carefully. Like he was reading pages she didn’t want him to see.

“You’re shaking,” he whispered.

“I’m fine.”

“Honey,” Thor said, voice dropping, “you are a terrible liar.”

Y/N sucked in a sharp breath. Thor noticed everything. Every mood. Every shift in tone. Every heartbeat that wasn’t steady.

“Did something happen in training?” he asked gently.

Yes.

Everything.

Too much.

“No,” Y/N said too quickly.

Thor lifted her chin with two fingers, making her meet his eyes.

And that was the moment she broke.

Her vision blurred. Her pulse hammered. Her breathing went thin and fast, like her lungs were full of smoke.

Thor’s eyes widened with worry. “Y/N… you’re afraid.”

She couldn’t speak.

He pulled her into his chest instantly, arms wrapping around her like a fortress. Normally, that made her feel invincible.

Today, it made tears flood her eyes.

“Talk to me,” Thor whispered into her hair. “Whatever happened—I can help you.”

God, he didn’t know.

He had no idea the thing she needed help from… was herself.

Y/N tried going about her day like normal.

She wasn’t normal

Every time she walked past Natasha in the hallway, her spine locked. Natasha wouldn’t look at her. Wouldn’t speak. Wouldn’t breathe in her direction.

Which made everything worse.

The kiss had cracked something open between them and then slammed it shut again, trapping everything inside Y/N like heat in an airtight room.

At dinner, Thor sat beside Y/N, laughing with Steve about something. Y/N stared into her food, barely hearing anything.

Thor leaned into her ear. “You haven’t eaten.”

“Not hungry.”

Thor frowned. Hard.

“You’re pale,” he murmured. “And your hands are cold.”

She shoved her hands under the table. “I’m fine, Thor.”

“You’re lying again.”

Her throat tightened painfully.

Across the cafeteria, Natasha got up and left without touching her tray.

Thor followed Y/N’s gaze.

His eyes narrowed. “Did something happen between you two?”

Y/N’s pulse exploded.

“No,” she said. Too fast. Too sharp.

Thor’s face darkened with something deeper than suspicion. Something he rarely felt.

Hurt.

Y/N didn’t sleep that night.

She eventually left the room and found herself in the training room again, the mats still faintly smelling like the moment she’d ruined her relationship and possibly her entire life.

A voice came from behind.

“You shouldn’t be here alone.”

Natasha.

Y/N swallowed hard. “I couldn’t sleep.”

Natasha stepped closer, stopping a few feet away, jaw tense. “Thor knows something’s wrong.”

“I know.”

“This is going to hurt him.”

Y/N’s voice cracked. “I know.”

Silence burned between them.

Natasha exhaled shakily. “I shouldn’t have kissed you.”

Y/N blinked hard. “I kissed you back.”

“That doesn’t make it right.”

“I know.”

“And it doesn’t make it wrong,” Natasha whispered, so quietly Y/N barely heard.

Y/N froze.

Natasha took another step toward her, then stopped again—like she physically couldn’t trust herself within arm’s reach.

“You’re with him,” Natasha said. “He’s good. He’s kind. He loves you more than anything.”

“I love him too.”

“But you kissed me like you didn’t,” Natasha whispered.

The truth didn’t need to be said out loud—Y/N had felt something she wasn’t supposed to feel. Something sharp. Something dangerous. Something that had Natasha’s name written all over it.

And Natasha knew.

Natasha always knew.

The door behind them opened.

Thor stood there.

Still. Silent. Eyes burning not with rage—but with heartbreak.

Y/N’s blood turned to ice.

Thor’s gaze shifted between the two of them, taking in the distance, the tension, the invisible thread pulled too tight between them.

“Tell me the truth,” Thor said, voice painfully steady.

Y/N couldn’t breathe.

Thor’s jaw clenched. “Did she touch you?”

Natasha stepped forward instantly. “Thor—”

“Did. She. Touch. You.” His voice was low enough to shake the floor.

Y/N’s chest collapsed. Tears burned her eyes.

Thor stared at her like he was watching the world fall apart in slow motion.

“Y/N,” he whispered, “please don’t lie to me again.”

Her lips parted.

She couldn’t say it. Couldn’t say yes. Couldn’t say no.

The silence was worse than either answer.

Thor’s breath left him like he’d been stabbed.

His shoulders dropped—not with anger, but with grief so heavy it bent him.

Natasha took a step toward him. “Thor, it was a mistake—”

Thor didn’t look at her. Not even once. His eyes never left Y/N.

“A mistake implies you didn’t want it,” he said quietly. “Did you want her?”

Y/N’s heart stopped beating.

She couldn’t answer.

And her silence answered for her.

Thor’s face broke in a way she had never seen—not in battle, not in pain, not in loss.

Only love could hurt like that.

He nodded once, too controlled. Too calm. The kind of calm that comes right before a storm or right before someone shatters.

i have done this before but