This is my first Avengers fic and I think I got a little side-tracked in the middle about the admantium so sorry about that

"If I were an enzyme, I'd be a DNA helicase so I could unzip your genes."

It took Bruce a second to realise what Tony had just said and when he did, he looked up with a sort of dazed expression on his face, sure he must've misheard. Judging from the way Tony winked at him, he hadn't misheard at all. Bruce could feel his face flushing and he had no idea how to respond but apparently Tony hadn't expected him to respond, as he grinned smugly to himself and turned back to his work. Bruce just shook his head choosing to pretend that whole conversation had never happened, and Tony hadn't just tried to use a science pick-up line on him until about five minutes later.

"You and I would undergo a more energetic reaction then Potassium and water."

Again Bruce looked up and raised his eyebrow silently asking, "Seriously?"

"What?" Tony feigned innocence and Bruce looked away again wondering how he even put up with this man most of the time but almost as soon as he did Tony spoke again. "How about you and I go back to my place and we can form a covalent bond?"

What the hell was he even doing? Everyone knew Tony was a joker and a playboy but, seriously? Now he was standing there, smirking to himself with his tousled hair and muttering equations under his breath and Bruce felt his pants get a little tighter. As much as he hated to admit it, he really was attracted to Tony and this was the worst position to be in if you were. He knew he was just having fun, because that was what Tony did but all the same he couldn't get those thoughts out of his head.

And still his tormentor carried on. "If I was an endoplasmic reticulum, how would you want me: smooth or rough?" He accompanied this question with a suggestive eyebrow raise and Bruce felt his heart start to beat faster. Oh god. He turned back to his work and tried desperately to turn his mind off the man on the other side of the room who he was pretty sure was humming "Sexy and I Know It". After a couple of minutes of pushing buttons on his computer screen without actually being aware of what he was doing Bruce realised this wasn't working at all, especially as he was really struggling to ignore the growing bulge in his pants, a fact made even worse when he noticed Tony walking over to him.

"Want a coffee? I'm getting one myself and you kind of look like you need one."

Cautiously Bruce nodded and mumbled his thanks, wondering if there were any more sexual undertones in that question somewhere, and if there weren't, why had he calmed down all of a sudden? His heart was beating faster and faster with a strange fear of what he'd do next and as he suddenly realised the closeness of the other man. Desperately he tried to think about anything else because he knew what would happen if his heart rate got too high.

Tony smiled innocently. "Jarvis could you make us two coffees please?" He called out to the robot and started to walk away but as he did he brushed his hand lightly across the small of Bruce's back sending shivers all the way through him. Bruce felt his heart rate getting even higher and he knew that this was the worst it had been in a long time. Over the last few years, of course he'd been turned on, but he'd learned his limit and he kept to it, otherwise he would've hulked-out. But now he was being driven right over his limit.

Now Bruce was having serious trouble keeping control; he could feel his heart racing and the other guy was trying desperately to fight his way out. It had been so long and god Tony was hot and all of these things would usually be good, but now they were just making his heart pump faster and faster until suddenly it felt as if all his restraints were gone. He briefly caught a glimpse of himself reflected in the window with shockingly green eyes and then everything went blank.

/

When he woke up Bruce found himself lying naked in the middle of the lab; well, pieces of the lab. Although he didn't remember anything, he was in no doubt that he must've hulked-out in the middle of work for some reason or another, so right now he was mentally beating himself up. How could he have been so stupid, what if he'd hurt someone? Fortunately it didn't look as if he'd left the lab so as long as he was alone everything was fine… Except he wasn't alone, he'd been with Tony. Everything came flooding back to him now and he began to panic.

"TONY!" He yelled, hoping the other man was somehow alive and well enough to respond.

After a few agonising seconds, Tony strolled into the room perfectly casually with a smile on his face. "Brucie! Glad you made it back, I was starting to get bored without you."

The doctor chose to ignore his friend's painfully cheery attitude and get to the more pressing matters at hand. "How are you? I didn't hurt-"

"I'm perfectly fine," Tony stopped him before he could get too far into the apology speech, "I saw you going green and got out of there before the big guy noticed me. And before you ask how I kept you in here, let me explain the genius idea I had." He ignored Bruce's sarcastic, "Oh yes please do," and explained anyway.

"See, I figured that if you ever did "go green" in here, you'd end up hating yourself if you got out and destroyed half the city. So I did some research and I figured that if there was anything that could keep the big guy in it'd be admantium. Just before you moved in I had them reinforce the outer walls to the tower and the lab with it."

Bruce was gobsmacked. "That must've cost you loads; you didn't have to do that, even for a billionaire that's expensive and you weren't even sure it'd work were you?"

Shrugging carelessly Tony replied, "Well it was the best shot I had. Besides, the price doesn't matter to me; it's better than you giving yourself all that grief because he got out there and smashed up some houses."

"You still shouldn't have spent all that on me. And why didn't you tell me about this before anyway?"

Tony genuinely thought about that for a couple of seconds before he answered as if it was obvious. "It never came up."

Bruce rolled his eyes. "You're a dick sometimes you know that?"

"Yeah sorry," Tony sat down on the ground next to Bruce, who hadn't been expecting him to take that comment seriously. However now they were on the same level, he had become embarrassingly aware of his nakedness and moved to cover himself up a bit better. Tony smiled and gave up his jacket to save his companion's modesty.

"So anyway I figured I should apologise. I mean it's my fault this happened; I didn't really think. I know I can be annoying but I didn't mean to make you angry or anything. Seriously, if I ever start to piss you off again please tell me, I'll try and stop."

Bruce sat in silence for a moment, not knowing how to respond. This was going to be an awkward explanation.

"No, Tony, it's fine. You didn't make me angry I promise and you never annoy me, you're the best friend I think I've ever had." He said sincerely.

As he'd expected Tony looked flattered at the last comment but perplexed by the rest. "Ok so why did you get angry if it wasn't my fault then? I mean you've got a pretty tight lid on it right?"

Bruce could feel his face burning as he looked anywhere but at his friend. Tony knew what he had been doing before Bruce hulked out and the man was a genius, he could put two and two together and guess what had happened.

"You're right, I wasn't angry. This has almost happened before once or twice, if my heart rate gets too high…" He trailed off there as he could see Tony trying to hide a grin and he knew he'd got the message.

With a smug smirk on his face the younger man said, "So like if you got really excited," he raised his eyebrow suggestively on the last word as if his meaning wasn't already clear enough.

At this point Bruce would rather have been anywhere else in the world than sat here, naked but for a jacket, on a pile of broken tables trying to explain to his best friend that he was the hottest guy he'd ever met. The most he could bring himself to do was nod in agreement and wait for the inevitable torment he was going to get from the man who was now looking extremely self-satisfied.

"So are you like celibate then?"

That wasn't the response Bruce had been expecting, but he wasn't complaining because this was much better than it could have been.

"Well I may as well be," he answered, almost with a smile. "See, no one really wants to get with a guy like me. Can't imagine why." He added sarcastically.

"Me neither," Tony muttered and their eyes met briefly for a second or two before Bruce's darted away again and he suddenly became hugely interested in the floor as he continued.

"But hypothetically I could do it. Just like I can control my anger, I know my limits and I can control my… excitement."

Tony got that smug look back on his face again. "So what drove you over your limits this time? Must've really been something if you reckon you've got a handle on it."

He looked up at Bruce mischievously as he began his deductions. "Well since you said you're not getting laid, and I doubt you get yourself off much," despite the accuracy of that assumption Bruce rolled his eyes because Tony was looking far too pleased with himself. "So I'm guessing it's been a while and all that frustration has built up and I released it for you." He concluded, smiling at how dirty that sounded, especially in this context.

"Yes I suppose that's why it happened." Bruce agreed trying to add a tone of finality to his voice and bring the conversation to an end.

But Tony wasn't done yet, "Or maybe there was something else that broke all your self-restraint? I mean you wouldn't be the first person to find me that irresistible."

"You really are modest aren't you?" Bruce pointed out sarcastically.

"It's just another one of my charms," Tony countered. "Come on admit it, you like me," he poked Bruce in the arm childishly trying to provoke a response.

Bruce fought back a smile. "No I don't."

"Do to."

"Do not."

"Do to."

"You're such a child sometimes." Bruce accused.

"If you'll just admit it…" Tony may as well have been begging by now.

The blush was beginning to come back into Bruce's cheeks and once again he avoided the eye of his friend. "Ok," he admitted, "Maybe a little."

"Yeah right," Tony sounded disbelieving. "I didn't miss everything that happened this morning you know."

There was an uncomfortable silence for a moment as Bruce realised he couldn't keep denying this forever. Tony was a genius and a dick and those two qualities didn't mix too well. It seemed they'd both realised this at the same time because just when Bruce sighed with defeat, Tony gave a triumphant grin.

"We should probably start cleaning this up or it'll never get done," Bruce suggested, seeking a way to end the conversation. "And I need some new clothes."

Tony gave him a suggestive look as he remembered the state of Bruce's undress. "Oh don't worry, you won't be needing them just yet."