Author's note: A little preamble here.

I write romance by second nature (and by romance, I refuse to specify smut or not smut). So I can honestly take any two characters, mine, or others, or invent them on the spot, and write an epic love story or short adorable fluff snippet out of nothing. I'm not trying to brag. I'm actually having to justify writing this to MYSELF. That's why I'm babbling.

Anyway, this was floating around my head for a couple days and I felt it was worth getting down on paper (well, print I guess). I'm posting it because I know I'm not the only one who appreciates a little Science Bros smush.

I also don't know a lot about Banner's family history, so I filled in the blanks with my own penchant for angst.

I apologize in advance to Stan Lee, Marvel, Bruce and the whole Banner family, Tony and the whole Stark family, Robert Downey Jr. and Mark Ruffalo.

Thanks for reading!

Tony leaned over his worktable. There was nothing in the world he enjoyed more than working. Tonight, he wasn't working on any lifesaving devices or world-altering technologies. He was modifying a 1970s muscle car engine to fit in his 1902 Ford Model T. This sort of thing was old hat to him; he'd done it a dozen times before. But he found peace in it. He relished the simplicity of an internal combustion engine. The power and strength created with steel and petroleum and American ingenuity. It was like his own Iron Man suit, in a way. And when the world got complicated, Tony retreated to his workshop to fiddle with his cars.

He was deeply immersed in redesigning a piston out of a smoother alloy when a tiny sound disturbed his concentration. Dr. Bruce Banner had just wandered into his workshop. Tony glanced down at the transparent screen floating before him at the time display in the corner. 4:42 am.

"What are you doing up this late, Dr. Banner?" said Tony, picking up a small wrench.

"I feel like asking you the same thing, but it's not my house and that would be rude."

Tony looked over at Bruce and smirked.

"I'll tell you if you want."

Bruce stepped closer and Tony noticed that he was wearing striped linen pyjamas that had clearly been a souvenir of India and a worn grey t-shirt. He looked adorably rumpled.

"I have trouble sleeping at night, so I mostly work through the small hours. I get my sleep in snatches through the day on my workbench, or a couple hours with Pepper in our bed," Tony explained, not looking up again from his work.

Bruce seemed hesitant. "Why do you have trouble sleeping?" went unasked. Tony knew Bruce was afraid to ask because he was a guest. He was shy. He didn't meddle in peoples' business. He was Bruce Banner.

He'd only been staying in Tony's Malibu mansion for three days. He probably didn't think he'd been there long enough to ask those sorts of questions.

It was nearly a year after the battle in Manhattan. Tony and Bruce's friendship had blossomed over their time together, looking for the Tesseract, but had been cut short by Bruce's fleeing back into the wilds after Loki was taken back to Asgard by Thor. They rekindled the relationship, however, every chance they got. There was a SHIELD meeting in Paris in November to discuss the best way for the Avengers Initiative to be revamped. In that time, Tony took Bruce to a science summit at the university there and they'd had a blast together. In February, a rogue terrorist group had threatened Los Angeles and the Avengers had been brought in to fight covertly (Barton and Romanoff) and overtly (the rest). Bruce and Tony bonded for two weeks while helping Romanoff track the terrorist group's movements through an algorithm Bruce created.

It was now April and Bruce had been injured in a rescue mission after the collapse of a mine shaft in South Africa. Rather than struggle with dirty water and second-hand equipment, he asked Tony if he could recover in safety and sanitation at Stark Tower. At the time, Tony was sunning on the beach with Pepper as Dummy served them drinks, so naturally Bruce was invited to Malibu instead. It was the first time in years he'd gotten to use fresh bandages on himself. It was a relief. And the first time in his life he'd ever gotten to sun on a beach. Hydrocodone, rest and a torso brace were all that were needed to treat the concussion, cracked ribs and mess of scratches and cuts he'd sustained in the mine after the secondary collapse.

Bruce had trouble admitting to Tony and Pepper that "resting" on Tony's private beach was more fun than he'd had in over a decade. Sometimes it seemed… like he was normal. The three of them became really good friends in those three days.

And now Bruce, with his pathetic limp and bruised face, was leaning over the counter, watching Tony work, still unable to ask what he was wondering. Around 5 am, he finally said, "Why can't you sleep?"

Tony looked up and two sets of brown eyes met in a dismal kind of understanding. Tony didn't need to say it.

"The cave?" Bruce said softly.

Tony nodded, returning to work.

After a long silence, Tony reached to the neck of his black tank top and tugged it down, revealing the scarred skin around his Arc reactor. "Sometimes, I'm… Sometimes it's my first night there. And Pepper's gotta hold my hands 'cause I'm trying to dig this thing outta my chest."

Tony watched Bruce's eyes as he separated the fresh scars around the steel from the old ones. He could tell that wasn't quite what Bruce was expecting, but maybe now, Bruce could open up. No one but JARVIS and Pepper knew about the nightmares. Only Pepper had kissed his lips to silence the screaming. Only JARVIS woke him with loud, familiar, American music as he begged unknown forces to let him die. Now Bruce knew. And… he was totally okay with that.

"You really trust me, Tony," said Bruce in a shy whisper, looking at the holographic screen, rather than Tony's face. It was a statement and not a question.

"I've trusted you since day one."

They smiled at each other.

Tony thought he'd answer his own question, making the step easier for Bruce. He said, "The accident?"

"Hmm?" said Bruce, turning a screwdriver over in his fingers.

"The gamma blast? Dr. Ross?"

Bruce smiled ruefully. His shoulders slumped and he set the tool back down in the catch tray.

"Everyone assumes that," he said, straightening and walking away from the work surface.

"It's not?"

"Sure, I have nightmares about… that… About… hurting her… About the lives the Other Guy has taken." Bruce stopped and put his hands in the pockets of the pyjama pants. He turned to look at Tony. "But when I wake up screaming, it's not the Other Guy that scares me."

Tony put down the auto parts in his hands and picked up a greasy rag, wiping his hands as he stepped around the work table to look Bruce over. Something told him this was something Bruce had never spoken about before. It needed saying. It needed to be shared. He was almost afraid to say anything for fear of saying the wrong thing and Bruce clamming up.

"What is it that does?"

"Him."

Tony couldn't imagine a "him" in Bruce's life more frightening than the Hulk. He was unstoppable and had hurt people. Bruce had decent control over him now, but that wasn't always the case.

"Him?" he repeated, thinking hard. "General Ross?" Tony knew that the father of the woman Bruce loved had tried to kill him, had tortured him, had pursued him across continents.

Bruce let out a dry, ironic laugh that Tony hated hearing. It was a laugh that hid a lot of pain.

"Actually, yeah, sometimes they are the same person in the dreams," said Bruce thoughtfully. "For a while, before the accident, the General was like a father to me. The way he turned on me… It was sick. But no, the person who terrorizes me in my nightmares is my father."

Tony paused. He hadn't read or heard anything about Bruce's parents save that they were dead. He knew Bruce had grown up in foster care. He assumed that Bruce had been an orphan since he was an infant. Clearly that wasn't the case. He made a mental note to have JARVIS fill in those blanks.

Bruce looked at Tony with the fear and uncertainty of a captured wild animal that didn't know if it was about to become dinner or a friend. His hands were fisted inside his pockets, clearly trying to hide the fact that they were shaking. His brown eyes sparkled in the work light under his tousled fringe, silently looking for approval or denial in Tony's.

Tony wanted to make sure he didn't frighten Bruce. He had to tread lightly. He walked past Bruce as nonchalantly as possible and sat down on a worn, rugged leather sofa that backed up to his red roadster. He motioned for Bruce to sit. To Tony's relief, he did.

"Tell me," said Tony as softly as he could.

Bruce shifted and curled his legs up under him in a way that reminded Tony eerily of Pepper. He tucked his fidgeting hands under his knees.

"Mom was always crying," said Bruce, staring at the floor.

Tony thought about how his own mother drank and cried and cried and drank alternately. Obviously, though, for different reasons than those of Mrs. Banner.

"She bruised so easily."

Tony thought his heart would break at the tone of Bruce's voice. That is, if it wasn't made of steel. He hadn't ever heard that much pain in someone's voice in his life.

"You didn't though," he said without thinking.

Bruce looked up at him with something between triumph, defiance and hatred on his face. "Yeah," he breathed.

"You took the blows," said Tony. "Like a man."

Bruce nodded, his eyes glistening.

"You never gave in. Never fell."

Bruce's shoulders trembled, as if supporting a heavy burden.

"You never cried."

And suddenly Bruce Banner broke.

Part of Tony knew it was some kind of healthy psychobabble thing, but part of him also never wanted to see someone he cared about look like that, sound like that, shake like that again. He wanted to reanimate Mr. Banner's rotted corpse just to tear him apart and make him tremble and sound and look like that.

Bruce was always aloof. The only emotion he showed, obviously beyond the Hulk incidents, was a good-natured self-depreciative humor. He exuded a kind of reserved strength, whatever it was that kept the Other Guy at bay.

Now, he was small. Trembling. Weak. His face was hidden in his hands as his frame shook with silent sobs.

Tony Stark didn't let his emotions get the best of him. But at this moment, he gave into an instinct he normally battled violently to the death. He wrapped Bruce in his arms.

Something changed in Bruce. Normally, when touched, he recoiled. He avoided human contact for the sake of those around him. Now, he too gave in to an instinct he normally fought desperately. He let Tony hold him. Tony felt the change. Felt the submission in Bruce's body as he fell into Tony's chest, his face pressing into Tony's neck. Bruce gave into need and collapsed into Tony's strong embrace. And it was a little frightening.

Tony sat silently for what felt like hours as Bruce – and Tony hated even thinking of the concept – cried himself out. He didn't notice the point when he started gently raking his fingers through the hair at the back of Bruce's neck. He didn't notice the point Bruce's arms snaked around his waist. He pretended he didn't notice that they were suddenly cuddling on his couch.

"I'm sorry, Bruce," Tony breathed. "I'm sorry you… ever had to feel that way."

Bruce was quiet, his sobbing slowing down to a pathetic trembling that Tony wished he never had to feel. "I'm sorry for breaking down. I just – "

"Don't be. Don't think that again."

"Okay."

"This is my home. My lab. My couch. My… my arms. You're not allowed to be ashamed while you're on my premises, capice, Banner?" said Tony, smirking down at Bruce.

Bruce smiled shakily, not wanting to look up and let Tony see the streaks on his face. He hoped Tony could feel the change in expression through his shoulder.

"Ready to go back to bed or you wanna stay here and watch me mess with shit a while longer?"

Bruce sat up and wiped his face on the inside of his shirt. He looked at Tony through the corner of his eye. "I'll only go to sleep if you promise to go to sleep too."

Tony shifted uncomfortably. "I can't."

"Why?" Bruce looked confused.

Tony sighed. "The only time I can sleep, really sleep, like more than forty-five minutes, is with someone beside me."

Bruce stared blankly.

"Know how I'm famous for sleeping around?"

Bruce nodded.

"The sex is fun. But I really needed to get some rest. A warm body in my bed was the only way to get a full six hours," said Tony, smirking a little more self-depreciatively than Tony Stark should have been capable.

"Six hours isn't full," said Bruce, matching the look. "So Pepper…?"

"The love of my life. And also the only way I catch any real Z's these days."

Bruce looked shifty. "So, you're up all night because she's in London?"

Tony nodded.

"And you do this every time she leaves town? She's in charge of 90% of your company. How do you rest?"

Tony knew there was an unspoken "without cheating on her" hanging on the end of that sentence. He shrugged. "I catch half hour naps on my workbench, or in board meetings."

This made Bruce snicker.

"When will Pepper be back?" he asked.

Tony thought. "JARVIS?"

"Miss Potts will return Monday evening at 7:45 pm, assuming traffic from LAX is typical," said the AI butler.

"Four more days without a solid night's sleep, Tony?" said Bruce, uncurling to stretch. "That's not healthy."

Tony shrugged again. "Since when do I live a healthy lifestyle?"

He had a very strong feeling that Bruce was hinting at something, but he really wasn't sure he wanted to open that can of worms, cross that line.

"All you need is a warm body beside you, right?" said Bruce, examining the floor.

Tony's heart skipped a beat. "Right…"

"You could sleep with me."

Tony was 1,000,000% certain he'd never seen Bruce Banner look that sheepish, that uncertain, about anything during their time as friends.

"Just, you know, so you could sleep," he clarified. Tony heard the unspoken, "No hanky-panky," on the end of that sentence, too.

Tony looked back at the project on his table. When his eyes fell on Bruce again, he knew there was only one answer.

"Sure."

Tony tried extremely hard not to give too much thought to the fact that he was now walking up the stairs to the living room with Bruce holding his hand. He tried not to give any thought to the fact that Bruce was escorting him to his guest bedroom. However, he was unable to think of anything except the fact that said guest room now smelled entirely and overwhelmingly of Bruce Banner, even in three short days. Tony ignored the fact that the mixed scent of Indian cooking spices, Moroccan incense and Ivory soap made his heart beat faster. For a little while.

Too late did the two realize Tony was in dirty work clothes and hadn't any clean pajamas. As Tony turned to go get some, Bruce tossed him another pair of linen pants, these with a faint, faded batik paisley print on them. Bruce sat on the foot of the bed with a folded white t-shirt in his hands as Tony peeled off his muscle shirt and wiped the oil and sweat off his face with it.

Bruce's room was so clean and cozy he actually felt bad for bringing his grimy self into it. But the look on Bruce's face as he pulled the white shirt down over his body told him it was okay. For some reason, Tony thought it was adorable that Bruce stared determinedly at the dresser while he changed pants.

"Tony," Bruce began, turning to face him. But Tony cut him off, without thinking, because thinking was a bad idea at this point. He knelt on the edge of the bed beside Bruce and kissed him.

What Tony was expecting, he certainly didn't know because, again, he was trying not to think. But what happened next genuinely surprised him. Bruce kissed him back.

There was this unspoken thing neither of them had even acknowledged until this moment that made everything, this whole mess, okay. It was nearly six in the morning and they were making out on Bruce's bed. And somehow it was fucking okay.

Tony didn't know what came over him when he swept Bruce into his arms and crashed into the bed, pulling the silk sheets up over them both. Was… was he… cuddling? Since when did Tony Stark cuddle? Apparently, since tonight. He pulled Bruce tightly against him and pressed kisses all over his face.

"Tony," said Bruce softly but suddenly, pushing gently on Tony's chest, "I can't, er…"

"Just this," said Tony, hoping he wouldn't have to elaborate.

Bruce blinked at him, one eyebrow quirked.

"Just. This."

A slow smile finally spread over Bruce's face and he curled into Tony.

Somehow, that meant more to Tony than anything so far this morning. He was, of course, incredibly confused about the whole feelings thing, but that wasn't important. He felt completely content with Bruce snuggled up against his body and he only wanted to focus on that.

Tony gave in to a very juvenile instinct and nuzzled his face into the curls on Bruce's head. Bruce let out a quiet, embarrassed laugh and buried his face in Tony's chest in turn.

Ask no questions. End up discussing no semi-homoerotic couplings you didn't know existed. They both felt like that was a good policy.

It was one of the strangest nights – make that mornings – that either of them had ever spent. And that was really saying something. They kissed. Slowly, softly, experimentally, like they were twelve. They touched. Only tentatively. Only, for lack of a better word, chastely, as if curious. They just snuggled the fuck out of one another. They dozed off as the sun rose, legs and arms tangled, faces pressed close from kissing, the scent of spices hanging low in the air over them. Neither of them woke from nightmares. Neither of them cried out. If they dreamt, it was of something beautiful. Pepper. Trees. Ramen noodles. Each other… And they slept. And they slept. And they slept.

They slept until JARVIS woke them the next day at 7 pm to tell Tony that Pepper had been calling all day, worried. They had slept soundly, deeply, in one another's arms for a full twelve hours. They both realized that it was longer than either of them had slept since they were children. And they both knew that neither of them could have done it without the other in his arms.