Disclaimer: Avengers belongs to Marvel, not me.

Warning: I don't write sex scenes often. I might not be very good at it.

Undone

In the Red Room, Natasha had been taught to not ignore her emotions. Emotions would be there whether you acknowledged them or not, and an emotion you denied, suppressed, or misunderstood could still sabotage you. They were conditioned instead to recognize their emotions, to identify them with clinical detachment, to keep them at a distance, to not let them affect behavior or even facial expressions unless it was useful.

Natasha could cry, easily, if she had to for a mission, to blend into a crowd or manipulate a mark, but thanks to her conditioning, it would only ever be an act.

And so she wasn't crying. She was staring out a window of a palace in Wakanda in the middle of the night thinking about her dead friends, going over every moment she'd ever shared with each of them.

That was when she saw someone leave the palace, walking toward the forest. She recognized him by his movement: Bruce.

This was where they had lost. This was where Thanos had won. Bruce remembered every moment of the battle.

It was weird. When the Hulk fought, he didn't remember the details. He certainly didn't remember the fear.

The Hulk wasn't afraid to fight. Bruce was. The Hulk was strong, fierce, fast. Bruce was just a brainiac in an average human body. He'd been useless in that battle.

He was useless. Thanos had just tossed him aside, imprisoned him in his oversized robotic suit. He'd watched uselessly as his friends fought, as they died.

He picked up a stick and broke it, just to know he could break something. It didn't help the sense of uselessness in his chest.

He tore a dead branch off a tree, the way he wished he could have torn Thanos's arm from his body.

He broke the branch in several pieces, and threw them as hard as he could, one by one, into the night woods. He didn't know why.

"Why?" he shouted into the night. "Why didn't you help them, you stupid green coward? You... just... let... them... die!"

He was out of pieces of stick to throw. He fell to his knees. He punched the dirt and choked back a sob.

"Don't be so hard on the big guy."

He looked up, startled at Nat's voice behind him.

She stepped closer to him. "I couldn't sleep."

It struck him as a shallow, disingenuous thing to say. But at the same time, it was such a Natasha thing to say that it was almost comforting. She was always so cool-headed and unperturbed.

"What are you doing out here?" he asked.

"I saw you walking out, and I wanted to make sure you were okay."

"Is anyone okay anymore?"

She didn't answer. She walked over and sat down next to him.

He stared at his hands. "I have no idea what I'm supposed to do now. What can we do?"

"Survive," she answered. "Regroup. The world is going to need the Avengers now more than ever."

"Even after we failed them?"

She sighed, giving up on trying to stay positive. "I don't know."

He looked at her. It was easy to forget the control she had over her emotions didn't mean she didn't feel them. She was probably hurting just as much as he was right now.

With that realization, he was suddenly no longer angry, either at her or at himself. He wanted to comfort her somehow.

He stood and hesitantly put his hand on her shoulder. She gave him a weak, brief smile, and covered his hand with her own.

With everything that had been going on since he got back to Earth, they hadn't gotten a chance to talk. He hadn't really even had a chance to think about their relationship. It had been years since they'd seen each other last, since the kiss they'd shared in Sokovia. Sure, he mostly couldn't remember those years, but she didn't have that problem. Did she even want to be with him anymore? She might never forgive him for running like he did. Or she might have found someone new.

Wherever they stood now, it wasn't a good time to bring it up. Especially not here, surrounded by the dust of their fallen friends.

"Want to go for a walk?" Nat asked. "I heard there's a nice waterfall around here."

"Now? It's the middle of the night."

"The moon is up. And I don't feel like sleeping. Do you?"

Bruce looked around at the battleground. "No. Let's go see this waterfall."

Something about the sound of falling water had always been soothing to Natasha.

"You know, I've had to deal with a lot of stuff in my past," she said, looking at the shifting glitter of the moonlight on the river.

"Yeah," Bruce said.

"I've found that sometimes, when I'm feeling just completely crushed, to get through it I have to take a step back, do something to remind myself happiness exists."

"Like sitting next to a waterfall?" Bruce asked.

"Yeah. Sitting next to a waterfall in the moonlight. Right now, I feel like I just lost almost everything." After a long moment, she added, "I'm glad I didn't lose you."

He turned away from the view of the waterfall and looked at her. He thought about the first time he met her, in that shack in India where she asked him to help S.H.I.E.L.D. find the tesseract. A beautiful woman, calm and collected in the face of a monster. He hadn't known what to think of her.

He looked at her. She looked back at him.

"I missed you," she said.

"I shouldn't have left. I was being a coward."

"Was leaving your idea, or Hulk's?"

"It was both of us. We were afraid of hurting you."

"I know." She lifted her hand to his cheek. Her touch was warm and firm. He covered her hand with his. It had been so long since anyone had touched him like this.

He'd tried to protect her by leaving. His efforts to protect her always felt clumsy and almost comically inept. She was so strong, both in body and will. He wondered what he had to offer her.

She saw the uncertainty in his face even as he welcomed her touch. She was still mad at him for running away, but right now wasn't the time to bring it up.

"You should stay this time," she said. "The world's gonna need you." More quietly, she added, "I need you."

He needed her too, he realized. After everything he'd lost, everything he'd been through, he needed her. Her touch, her presence felt like medicine. He leaned forward and touched his lips to hers.

Her free hand went around to the back of his head, holding him in the kiss. The hand on his cheek turned beneath his hand. She interlocked her fingers with his.

His touch sent a tingling through her body, from her lips and her hands down her insides to settle between her legs. Her lips moved over his hungrily. Her tongue flicked out, running along his lips, then sliding between them.

He returned her kisses for a minute, then drew back without letting her go. "Natasha, are we sure about this? I mean, is this the right time?"

"I'm sure that for the first time since the battle, I feel like the world isn't ending. I feel like I can get through this. You do that for me."

He nodded. "I...kind of feel the same way. Like, with all the bad, I need to remember there's something good."

"Just kiss me," she said. "Nothing else has to happen tonight, if you don't want it to."

He wrapped his arms around her back and pulled her to him, kissing her obligingly. He honestly hoped something else would happen tonight; it had been years since he'd made love, not since before the Hulk. But now the Hulk wasn't coming out. And he was with Natasha.

He paused in a kiss, and drew back to gaze at her.

"God, Nat, you're so beautiful."

"I know. And that's literally the least interesting thing a man can say about a woman, by the way," she mentioned.

"Kind of killing to mood," he said, but smiled.

"Sorry. Go on."

"You're strong, you're smart, you're the bravest person I've ever met. What does someone like you see in someone like me?"

"Right now, I see someone who could be making out but would apparently rather leave me hot and bothered by blathering about how you don't deserve me. You know my past, you know my flaws. You also know you're a soft, sexy supergenius superhero, not exactly a charity case. Get me off this goddamn pedestal and touch me, Bruce."

He chuckled. He resumed kissing her, allowing himself more initiative. He left her lips to kiss and suckle her neck. She moaned, and at the sound he felt himself grow hard.

His hand trailed up the curve of her waist from her hip to the side of her breast. His thumb traced light circles over it. He returned his mouth to hers, plunging his tongue between her teeth. Her tongue moved to greet it.

His fingers trailed from the side of her breast toward its center. She hadn't put on a bra when she'd quickly dressed to follow him into the forest. She moaned as his thumb rubbed her hard nipple through the fabric of her light teeshirt.

He left her mouth and pressed kisses to her chest. She ran her fingers through his hair.

"You know," she said, her voice husky with desire, "the night we met, when I was trying to recruit you to the Avengers, I was prepared to have sex with you if I thought that would make you more likely to say yes, if you'd been that kind of guy. I used to do that kind of thing all the time. And I would have enjoyed it. You were cute, in a lost-puppy kind of way. But I'm glad it didn't go down like that. I'm glad I got to know you first, got a chance to really fall for you."

This revelation just confirmed what he'd already suspected. "I'm glad you didn't try anything back then," he said. "If you had, I'd never know if you were really interested, or if you just wanted something."

"I do want something," she teased. "You." She shifted to wrap her legs around his sides. Guiding his head, she pressed her nipple to his lips.

He nibbled her nipple through her clothes. She shifted her hips forward, rolling her crotch against his abdomen.

"Do you want me?" she whispered.

"I want you," he replied. "Oh, God, I want you." He lifted her teeshirt, slowly, trailing his fingertips along the smooth skin of her back. She lifted her arms to let him remove her shirt entirely, dropping it behind her.

He gazed at her for a moment, her skin glistening in the moonlight, then he returned his mouth to her breasts, licking and sucking her right nipple, then her left.

She lowered herself down his body until her crotch brushed the bulge in his jeans. She pulled off his shirt just as he had hers and dropped it behind her. She pressed her lips to his while lightly brushing her nipples over his bare chest.

He ran his fingertips up and down her spine, making her shiver. She broke off their kissing and drew back to look at him, drinking in his face, the moon reflected in his eyes as he gazed up at her.

She ran her hands down her own body, squeezing her breasts, running down her abdomen and between her legs. She unbottoned his jeans, then slowly pulled the zipper down. He gasped as her thumb grazed the tip through his boxers.

"You okay?" she asked.

"Yeah."

"We can stop if you want."

He shook his head. "I want this. I want you. I want you so bad, Nat, you don't even know."

She took his hands and rose off his lap, standing between his legs. She placed his hands on her hips, tucking his fingers under the elastic of her shorts.

He slowly slid her shorts and underwear down her legs to pool at her feet and took in the sight of her, standing naked in the moonlight like some kind of primordial goddess. He ran his hands back up her legs, feeling the powerful muscles of her calves and thighs, her glutes. He moved forward, kneeling in front of her, and kissed her mons veneris.

"Feel how much I want you," she whispered.

One hand caressed the inside of her thighs, then higher. He curled a finger into folds, warm and so wet. He watched her face as he touched her, watched her eyes close in rapture, her breasts heave with her breaths.

He slid two fingers inside her while his thumb rubbed her clit.

"Ah," she gasped. Her knees buckled, and she slid down further on his hand.

He responded instinctively by pressing harder into her, squeezing her. She writhed against him as a second orgasm gripped her.

He wasn't sure if he was going to make it much longer. He was hard and throbbing, his pulse was racing.

She drew away from his hand and pushed him to the ground. The rock below him had been worn smooth by centuries of floods. He closed his eyes and focused on the way it felt beneath him, bit his lip to distract himself from the feeling of Nat pulling his pants and underwear off, then the feeling of her legs at his sides as she positioned herself over him, and the sensation of a warm, wet, welcoming pressure sliding slowly down his shaft.

He moaned as she squeezed him. He grew light-headed, practically dizzy with pleasure as she moved up and down over him. He wanted to look at her, but knew the second he did he'd come undone. He didn't want to yet. He wanted this moment to last. He wished it could last forever.

And then something gripped him without warning, bubbling up from the inside. Oh God! Not now!

Nat was lost in a haze of bliss, free from thought, free from worry, in an almost trance-like state when she heard Bruce cry out in fear. A second later, she felt his muscles tense, felt him expand beneath her.

She slid off him, rolling to her feet. The Hulk sat up, looking dazed.

Her mind weighed her options: 1. Run. 2. Hide. 3. Face him.

Running had some risks. For one thing, in the dim light it would be easy to slip and fall on the slick rock. Also, she was completely naked. There weren't a lot of places to hide nearby.

She would stay. She'd handled the Hulk before.

"Hey there, big guy," she said softly.

His head jolted in her direction. He moved toward her, half crawling.

"Pretty girl."

"You've been gone a long time. Where've you been?"

"Sakaar. Hulk was big star on Sakaar."

He seemed more rational than she'd ever seen him before. That was good. "I missed you."

He reached for her. She didn't flinch as his giant hand approached her head. He ran a single finger through her hair.

Then he drew back, snarling. "Pretty girl didn't miss Hulk. Missed puny Banner."

"I did miss Banner, but I missed you, too. I missed you both."

"Pretty girl love Banner?"

When he asked this, she could see a flicker of something across his face. Her life depended on reading him and figuring out just the right thing to say.

She'd deliberately brought the Hulk out in Sokovia. He'd remember that. He'd also know what she and Bruce had just been up to; she couldn't lie to him, even if he didn't have the evidence of her nudity and his own erection to go by.

Her eyes drifted up and down his body, his face, which was bore a resemblance to Bruce's beloved features, his bulging muscles, his long, strong arms and legs.

Bruce and the Hulk were two sides of one personality.

"I love you both," she said.

Hulk was momentarily caught off-guard by that confession. He stared at her, unsure whether to believe her.

She stepped toward him, moving into his space. She placed her hand on his cheek. The moonlight was bright enough to capture the vibrant green of his skin, his face. Bruce's face.

"You're beautiful," she whispered.

He looked at her with surprise. She took another step closer to him and pressed a kiss to his oversized lips. She felt him trembling beneath her touch. His hand, shaking, came up to wrap around half her waist.

She wrapped her arms around his neck, pressing herself against him, and whispered in his ear. "Be gentle with me, Hulk."

"Hulk gentle," he said, voice trembling. "Hulk so gentle."

"Lie down. Me and Banner were in the middle of something. You and I are going to finish it."

He lay back on the rock, mirroring the position Bruce had been in just two minutes before. He was giant everywhere. The corner of Nat's lips lifted as she recalled the joke Stark had made during the battle of Sokovia about her and Hulk playing "hide the zucchini." That was pretty accurate.

She lay down on top of him, her arms around his neck, her breasts against his chest, and kissed him, mouth open. His body thrashed beneath her, wanting.

She kissed his neck, sucked on his earlobe. His hands gripped at the rocky ground beneath him as he struggled against the urge to take her.

She shimmied her body down his, trailing open-mouthed kisses down his chest, until she felt his throbbing shaft between her legs. She clamped her thighs around him. Her muscular thighs, toned from a lifetime of ballet and fighting. Those thighs had taken down opponents three times her weight. Those thighs had strangled people to death on occasion. Now she employed them for a much more enjoyable task.

Hulk moaned in pleasure as she flexed her muscles, squeezing and rolling his shaft between her legs. She imagined other things she could try: her hands, her lips and tongue on his tip. The fantasies caused her own breathing to quicken as she shifted to rub his shaft against her clit. She was so close...

The Hulk suddenly arched his back and roared. He went limp between her legs, leaving a splash of semen on her thighs.

Nat rested her body on his, feeling him panting. His body relaxed, sated, then shrank back. In a moment, it was Bruce lying beneath her.

He looked up. "What happened?"

"Hulk," she answered.

"Did he...did we hurt you?"

She chuckled. "No. He was a perfect gentleman."

"What...what happened? What did you do?"

"Don't get jealous, Bruce. We made love."

"How?"

"Use your imagination." Smiling, she kissed him, then pushed herself off him and walked toward the waterfall.

He looked her over, checking her for bruises or any other sign of injury. His eyes fell to her thighs, to the evidence Hulk had left there, and he suddenly figured it out.

Nat washed herself off with a few splashes from the frigid river, then went back to him.

"How are you feeling?" she asked him.

"I feel...good. Really good, actually. Satisfied." He shook his head, still not sure how he felt about Nat and the Hulk. "How do you feel? I mean, are you...are you satisfied?"

She smiled teasingly as an idea came to her. "Not yet. The Hulk disappeared before he could finish the job."

She lay down on the smooth rock and spread her legs. She ran her hand down her body, between her legs, and began touching herself, slowly, teasingly, working herself back up.

He watched her for a minute. Then, just as she hoped he would, he knelt down between her legs. "Let me."

She moved her hand out of the way.

Bending down, he parted his lips and touched the tip of his tongue to her clitoris. He licked it, then drew it between his lips and gently sucked. His fingers slid inside her, moving in and out as his lips and tongue sent the most delicious sensations through her.

She came fast and hard, gasping and writhing before her body settled into stillness. She drifted down into a state of dreamy contentment.

Bruce pillowed his head on her stomach. She stroked his hair.

"Thank you," she said. "I needed that."

"So did I."

They fell silent, listening to the soothing thrum of the waterfall. Now that it was over, the memories began to creep back. The horror, the sorrow, the failure. But it wasn't as sharp now. It wasn't as crushing, now that they had each other. It no longer felt like a fatal blow.

A pale blue was beginning to spread across the eastern horizon.

"Let's get back," Nat suggested. "We should get some sleep."