Title: The Science of Love
Rating: PG/K+
Originally posted: August 2015
Originally written for: a challenge at Avland on Livejournal
Characters/Pairings: Tony & Bruce (mentions Pepper/Tony, Bruce/Darcy)
Notes: Ties into Avengers in Babysitting & Can't Fight the Feeling (both available on AO3) but can be read as a standalone.

"It'd be easier, wouldn't it?" said Tony as he stepped into the lab. "If everything could be figured out in the math. If there was a scientific explanation for all of this wacky stuff we go through?"

Bruce didn't answer at first. He just stood staring at the screens in front of him as if he hadn't even heard what was said to him. Just when Tony was about to repeat himself, the good doctor reacted with a sigh.

"There used to be once," he said, pulling off his glasses. "I believed there was nothing science couldn't explain, given enough time and resource. We could unlock the secrets of space, discover micro-particles, cure all diseases, end wars..."

He shook his head then, voice trailing away to nothing. Still his eyes scanned the glass-like screen before him, confused beyond measure more by what he couldn't see there than what he could. Bruce flinched only when the screen was pushed roughly aside, and there was nothing else to do but face Tony head on.

"It's been a while since it was real easy to hide behind the test tubes and equations, doc," he reminded him. "Demi-gods, super soldiers, alien armies," he listed too easily.

Bruce smiled at that.

"Those I have some explanation for at least. Asgard has advanced alien technology. The Captain was injected with a serum. Even wormholes in space can be explained with high level math and physics," he assured his friend. "This is more than that. This is the question that's plagued mankind from the beginning."

"Yeah." Tony sighed. "Never expected it to happen to me though."

"Ha!" Bruce reacted with genuine humour. "iYou're/i surprised? Imagine how I feel. You may have been an asshole in the past, Tony, but that's not a trait that's impossible to love, and Pepper is a special woman."

"I'll agree with that. All of it, actually." His friend smiled. "But Darcy is special too. C'mon, a political science major who took on a man that fell from the sky with a taser? That's not your every day kind of gal."

"Agreed." Bruce nodded, a smile playing at his lips that he couldn't help. "You think anybody is ever supposed to understand the science of love, Tony?"

"See, that's where you're going wrong, big guy," his friend told him, slapping him on the back as he turned Bruce towards the door of the lab. "Love is not a science. It's a disease with no known cure. There is however a way to help ease the symptoms in times of trouble."

"Which is?" asked Bruce as they headed for the door, Tony's arm around his shoulders.

"There's this little thing called tequila..."