Tony had been hiding in his lab for going on six days. He had locked the doors and was letting no one in, not even Pepper, despite her constant protests. Natasha had tried to sweet talk him out, while Steve tried to order him out, both of which failed miserably because he knew exactly what she was doing and shut off all forms of communication into the lab. Clint planted explosives around the lab, and Thor tried to smash his way in with the hammer, despite Bruce telling them it wouldn't work, that Tony had already Hulk proofed the lab, and most of the house for that matter. Bruce tried to hack into the computers and unlock the door, but he knew it was pointless because Tony was a hell of a lot smarter than he was, and JARVIS was tough to get past. Pepper tried to bribe him with food, but even that he seemed to be prepared for, having stocked the lab with enough food to last him a month, if necessary.
It was the middle of the night on the seventh day when Tony finally exits the lab. Most of the team was fast asleep in their respective rooms, but Bruce was sitting on the kitchen counter, eating a bowl of macaroni and cheese.
"Can't sleep?" Tony asked, walking over to him.
"Haven't gotten a full night sleep in year," he said, though Tony already knew this, they'd talked about it before. "What brings you out of the lab? Am I allowed in again?"
"Aww, did you miss playing with my equipment?" There was no way to not read that as a euphemism, especially with the look Tony was giving him. And was he imagining things, or was he standing ridiculously close?
"What were you working on in there? Why have you been hiding from everyone?"
"Not everyone," Tony said. "Just you."
Bruce raised an eyebrow, unsure just how insulted he should be.
Tony grinned as he took his bowl of macaroni and set it on the counter, then took Bruce's hands in his own and pulled lightly.
"Come see," he said.
Bruce gave him a strange look, but slid off the counter and allowed himself to be dragged down to the lab.
"Nothing looks different," he said slowly. Frankly, he'd been expecting the lab to have been torn apart and put back together, which was what usually happened when he started a new project. The only thing out of place was the rather large gift box sitting on a counter.
"Well," Tony prompted. "Are you going to open it?"
Bruce stared at the box. "W-what?"
"Don't act so surprised," Tony said. "Your birthday is tomorrow. You think I forgot?"
In all honesty, Bruce had forgotten. It had been years since he'd celebrated his birthday.
"You… got me a present?"
"Made," Tony corrected. "Made you a present."
"You made me a present."
"Yes. Are you going to open it?"
"Is it going to explode when I do?"
Tony grinned. "Maybe. Won't know until you try."
Bruce cautiously stepped forward and tugged at the giant green bow, then pulled away the paper. Inside the box was… another box, wrapped in bright pink paper.
"JARVIS," Tony said, only slightly annoyed. "Didn't I specifically say not to use that paper?"
Bruce opened the second box and found a third box. Inside that, a fourth box
"Tony, did you get me a bunch of boxes? Because, as much as I appreciate it-"
"Just open it!" Tony exclaimed, the anticipation clearly affecting him more than it was Bruce.
Inside the fourth box was, not surprisingly, a fifth box. However, inside the fifth box was…
"Pants?" Bruce asked, holding them up. They looked like normal enough pants, but were made of a strange material he was sure he'd never felt before. It felt almost like running water through his fingers. "Purple pants?"
"Yes. To match your purple shirt of sex."
"Purple shirt of… sex?"
"Oh, did I say that out loud?" Tony asked. "I meant to say that purple shirt you wear that makes me want to have sex with you. Then again, I pretty much always want to have sex with you, so I guess the purple shirt has nothing to do with it. But I like the purple shirt, so I made you purple pants."
Bruce stared at him for a moment, then stared at the pants, then at Tony again. "Why?" And, more importantly, why had he locked himself in the lab for six days because of it?
"Oh!" Tony exclaimed. "I forgot to tell you the best part. This is what I've been working on, trying to get the material just right. I had loads of failures," he nodded off toward a giant box filled with, presumably, pants. The box was labeled 'Charity' (clearly JARVIS had gotten a hold of the label maker again). "But these," Tony smiled. "These are glorious."
Bruce blinked, wondering just what exactly made these pants so special.
"They stretch!" Tony exclaimed, seeing his confusing (though he obviously was getting some kind of satisfaction from it). "I've run dozens of tests. They won't rip when you Hulk out, so you'll never find yourself lying naked somewhere after you de-Hulk. Stretchy pants!"
Bruce's mouth was hanging open in shock, while Tony bounced back and forth, a wide grin on his face, waiting for his reaction.
"Stretchy pants…" Bruce said. "That's… amazing."
Tony's grin grew. "I'm glad you think so. JARVIS has already started making more. Shirts too. You never have to find yourself naked again-"
Bruce kissed him.
Tony hummed in pleasure. "Except maybe right now. Can we be naked now?"
Bruce laughed and kissed him again.