Chapter 1
You never meant to fall in love with Natasha Romanoff.
It happened slowly, like poison seeping through your veins – familiar territory for two ex-assassins. Training sessions that lasted longer than necessary. Lingering touches during mission briefings. Shared bottles of vodka at 3 AM when the nightmares wouldn't let either of you sleep.
"Your form is sloppy today," she'd tease, pinning you to the training mat for the third time that morning. But her hands would stay on your wrists a moment too long, her breath warm against your neck.
You knew better than to want her. HYDRA had taught you that love was a liability, beating that lesson into you until it was carved into your bones. But Natasha had a way of dismantling every wall you'd built, one smirk at a time.
The first kiss happened after a mission gone wrong in Budapest. Blood on your hands – not yours – and her lips tasting of adrenaline and fear. You both blamed it on the near-death experience. Then it happened again in the compound's elevator. The training room. Her quarters at midnight.
"This stays between us," she'd whispered against your mouth, and you'd nodded because secrecy was the only language you both spoke fluently.
For six months, you lived in stolen moments. Quick touches in empty corridors. Coded messages in mission reports. Nights spent memorizing every scar on her body, every sound she made when you touched her just right. You learned that the Black Widow snored softly in her sleep, that she liked to be the little spoon but would never admit it, that she hummed Russian lullabies in the shower when she thought no one could hear.
But you were never good at holding onto beautiful things. HYDRA had made sure of that too.
"I can't do this anymore," you told her one night, your voice steady even as your heart shattered. "I'm not built for this, Nat. I'll only break you."
She didn't cry. Natasha Romanoff never cried. But something in her eyes died that night, and you added it to the long list of things you'd destroyed.
Watching her fall in love with Steve Rogers was like dying in slow motion. He was everything you weren't – whole, untainted, capable of love without poison edges. You saw how he made her smile, how she softened around him in ways she never could with you. Because you were both made of the same sharp pieces, too jagged to fit together without drawing blood.
Bucky understood. Of course he did. He carried the same HYDRA-shaped holes in his soul.
"You're watching her again, doll," he'd say, metal arm cool against your skin as he pulled you away from another team meeting where Natasha sat too close to Steve.
You fell into Bucky because it was easy, because he was broken in all the same places. He kissed like he was seeking redemption, and you gave him everything you could. But you both knew the truth – his heart belonged to Steve as much as yours belonged to Natasha.
"Does it ever stop hurting?" you asked him one night, tangled in his sheets, both pretending you weren't thinking of other people.
"Nah," he'd replied, pressing his lips to your shoulder. "But eventually you learn to breathe around it."
The worst part was how Natasha looked at you and Bucky. Like she wanted to break his other arm. Like she wanted to kiss you until you remembered how perfectly your bodies fit together. Like she regretted letting you go.
But that was the thing about spiders and assassins – you were all experts at wanting things you couldn't have.
During missions, you still moved in perfect sync with her, muscle memory too deep to erase. In briefings, your eyes still found each other across the room, old habits dying hard. And sometimes, when the nightmares were particularly bad, you'd still find yourself outside her door, hand raised to knock before you remembered you'd lost that right.
Steve made her happy. You reminded yourself of this every time you saw them together, every time she laughed at something he said. He could give her everything you couldn't – stability, wholeness, a love that didn't taste like gunpowder and regret.
"You still love her," Bucky observed one evening, no accusation in his voice.
"Always will," you admitted, because lies had no place between two people using each other to forget.
That was your punishment, you supposed. To watch the only person you'd ever truly loved find happiness with someone else. To know that you'd had everything you wanted in your hands and let it slip away because you were too scared to hold onto it.
Some nights, when sleep evaded you, you'd find yourself in the training room, punching bags until your knuckles bled. Sometimes Natasha would be there too, and you'd spar like old times, pretending the tension between you was just adrenaline and not years of unspoken words.
"Are you happy?" she asked once, pinning you down just like she used to. But this time, she didn't linger.
"Getting there," you lied, because the truth would break whatever fragile peace you'd managed to build.
She nodded, helping you up, her hand warm in yours for one brief moment. "That's all I ever wanted for you, Y/N."
You wanted to tell her that happiness had red hair and green eyes and tasted like midnight vodka. That it was currently wearing Steve's dog tags and sharing his bed. That you'd had it once, but you'd been too broken to keep it.
Instead, you smiled and walked away, like you always did. Because that's what assassins do best – we disappear into the shadows we cast, carrying our hearts in bullet-riddled boxes, loving people we can never have.
And sometimes, on very quiet nights, you could almost convince yourself it was enough.