A/N: Hi. So this short plot suddenly appeared in my head when Natasha said the words to Bruce during one of the first parts of the movie, when she was supposed to get him to SHIELD. Yeah. Enjoy, people. Mark Ruffalo's a hot mess. Okay. Bye.

DISCLAIMER: Do not own anything. Period.

I'll persuade you.

As Natasha Romanoff said it, she regretted it. Those three words, especially when directed to a man, could mean absolutely anything. And when she had said it to the man in front of her, the infamous Dr. Bruce Banner, she crossed her fingers that he didn't hint anything.

Of course, she would be lying if she said he wasn't attractive. She wasn't ready to face the fact when she got there that this guy who had some serious anger issues was actually quite good looking, with the tan skin, rich black hair, and mysterious brown eyes. But there were also several reasons for her to avoid showing any affection. First of all, she had already said it. The other guy could appear at any moment he'd let go. Second, it was completely absurd to even think about it.

Dr. Banner squinted a little at her words, but other than that, his expression was unreadable.

"I didn't quite catch that," he replied, looking sincere about it.

Natasha rethought her words. Then she decided to reword it. "I'd find ways to get you to say yes."

Whoops. That came out wrong too.

She was glad that Bruce wasn't just a typical jerk, who would question what she had said, and taking it wrongly. After all, he was a scientist - an intelligent person, sophisticated.

Yet there was something in his eyes that she couldn't quite place.

Banner looked away, puckering his lips while deep in thought. He fidgeted a little as he paced a little. Natasha couldn't help but think that this man looked adorable when he was thinking.

"No," he finally said, waving his hands, as if it was final. "I absolutely refuse. I'm sorry, Agent Romanoff."

Natasha felt agitated. This mission involved her best friend, and she will not let this guy ruin her plans for saving him. She would do anything to save Clint.

She stepped closer, and Bruce instinctively stepped backwards. "Listen, doctor," she said, her voice full of poison. "I said I will persuade you to say yes, and I don't break promises."

"I apologize," Bruce said slowly, giving her an apologetic smile. "But I think you'll have to break one today."

He turned around to walk away from the abandoned house, and Natasha only had a few seconds to think this through. It left her no choice.

And now she knew what that 'thing' in his eyes were. It was undoubtedly lust, even though he didn't mean to show it.

She had to count on that.

She made a small growl before stalking toward him, gripping his forearm, and turning him around. It obviously took him by surprise, but nothing compared to what he felt after.

Natasha captured his lips with her own, all her hatred and confusion pouring over his surprised mouth. It was hard and rough, and she had to grip Bruce's shirt tightly for him not to pull away. She knew he was only doing so as a sign of politeness, because deep inside, he liked it. Whether it was good or not, he did.

He groaned, squirming. But she didn't let him. It was a bit weird, since he could just hulk out and she'd be dead.

But he didn't. Another reason for her to think he really liked it.

"I will not stop unless you say yes," she muttered between lip locks. But he still resisted in saying it.

She pushed him against the nearby wall, and that was when she felt his resistance gradually lessening, and his lips moving against hers. It felt absolutely glorious, and electricity sparked between them. His hands were on her waist all of a sudden, and she shuddered at the cold contact.

She let go of his grip on his shirt, moving them over his chest. Not only was this guy smart, but he was probably athletic too. Or maybe it was manual labor. But she didn't really care at the moment.

Her lips betrayed her by escaping a soft moan. He was startled a little at her reaction, but did not stop.

She suddenly felt pressure over her and she was suddenly the one pushed against the wall, and not the other way around. There was something stirring below her navel, and she knew exactly what it was. There was no way out.

"Say it," she said. He didn't reply.

His lips went lower, giving kisses along her jawline, and finally on her neck. She moaned again. It was perfect. She didn't want it to stop.

He sucked at one spot, which he probably noticed she moaned the loudest at. She couldn't stop it anymore. It was insane.

Without realizing it, her fingers suddenly had a mind of its own and started unbuttoning his polo. He didn't even stop her, and continued to kiss her neck. Natasha didn't know where this was going, and when this will end. But for now, she settled on letting it move forward.

The stirring down there got worse when she felt something against it. Shit. An arousal.

"Say it," she pleaded again, but half-heartedly now. She didn't actually want him to say yes yet, because that would mean to stop this beautiful - but insane - thing.

Luckily, he didn't. He lifted her suddenly, like she's just as light as a feather. She gasped at the act, and wrapped her legs around his hips.

He moved somewhere else, and Natasha just closed her eyes. This was all going too fast, but she didn't complain. It was a perfect fast.

She was surprised when she was dropped on her back on a wooden table. Bruce was still above her, but his feet were in the ground. He kissed her on the lips again, and something sparked.

"I could say it now, to stop this madness," he murmured between kisses. "I don't want to do something you'd regret doing."

She continued to fiercely kiss back. After a millisecond, she decided.

"Don't say it yet," she murmured back, her voice filled with want. "Please."

He didn't say anything anymore, but zipped down her suit until her navel. The cold air outside burned through her pale skin inside.

He kissed lower again, but onto her chest this time. She murmured his name, or was it just a moan? She couldn't recall anymore.

He finally had the guts to pull down her black bra, revealing modest handfuls of pale breasts, which he each kissed tenderly. She wanted to scream, feeling her core being impatient, and burning. He licked and teased, and she couldn't take it anymore.

"Please," she said. "Just do it."

"Do what?" he asked.

"It. I'm burning, doctor."

He finally understood, zipping down the whole suit. He helped her out of it, and she saw his brown eyes marvel a little at her frame.

"Last call, I could stop this," he said.

"Don't," she replied simply.

Without another word, she helped him zip down his trousers, finally revealing that he was very well aroused. Weirdly, she was still flattered that she was able to let him get this far.

Then she realized it was shameful of her to be the one under, so with a swift and slick movement, she turned him over, and stood over him.

And finally, she sank to him, filling him inside of her.

The pain subsided quickly, and she moaned. And for the first time, he did too. Pain was quickly replaced by pure pleasure, and she continued to buck her hips up and down in a rapid movement, taking everything of him inside of her.

"Shit," he swore, kissing the crook of her neck. She placed one hand on his toned chest, groaning as she felt herself going there.

The pattern suddenly disappeared, and they met without any particular speed. At some point it was extremely fast, but at another time they met with tender passion. But in the end, they came at the same time.

"Holy-" was all Natasha could muster as he felt his release.

Bruce didn't say anything, but he closed his eyes. They stayed that way for a long while, just standing over each other, still connected. Natasha felt that if she disconnected, she would feel absolutely empty.

"Say it," Natasha whispered.

With a little hesitation, Bruce opened his eyes. "Yes."

She realized that she went through all that just for a single three-lettered word, but she didn't exactly complain. It was beautiful sex.

But she really didn't know what it meant afterwards. Holy shit, she didn't think of that at all.

Reluctantly, she stood up, and sure enough, she felt empty. She zipped up her suit, and combed her hair with her hand. Bruce also sat up, zipping up his trousers and buttoning his shirt again.

"Thank you," they both said at the same time, and they looked away. It felt absolutely awkward.

"I'll pack," Bruce finally said.

Before he went out of the abandoned house, he stopped and turned to her.

"You're right, I don't doubt that you keep promises."

Then he walked away.