It started with a sniffle. Bruce noticed it first, as he and Tony spent hours upon hours in the lab with one another that it could almost be considered unhealthy. Almost, because Steve would always rescue them, at one point or another, from themselves. They had been working steadily over a new bot, one that had two fully jointed five fingered hands, and Tony had sniffled exactly five times in the past hour, and he kept wiping his nose with his wrist.
Bruce, having been around enough sick people to notice the symptoms of a cold, raised an eyebrow at his lover after the sixth sniffle and wiping of the nose.
"Are you feeling alright Iron Science?" he asked mildly, his brow furrowed with concern even as he smiled at the nickname.
Tony waved his hand vaguely and nodded, waving his screwdriver about as he tweaked something in the joints of the robot. "Fine, fine. Healthy as a horse. Hand me that soldering gun, yeah?"
Bruce's frown deepened, but he said nothing further on the subject as he an Tony worked on the bot, pointedly ignoring any further sniffles, knowing that pressing the subject would only make Tony angry and put him on the defensive.
The next day brought a light cough that Steve noticed in the kitchen as Tony putted about his expresso machine. He sniffed, twice, and then covered his mouth as he coughed, relatively gently but for far longer than could be considered a tickle in his throat.
"You feeling okay?" Steve asked, his brow furrowed in concern as he wrapped an arm around his lover.
"Great, just got a scratch in my throat," Tony said, worming his way out of the other mans grip. Steve frowned, but let the subject drop. If Tony wanted to ignore his budding cold, far be it from Steve to deny him that. He, of all people, understood what it meant to feel vulnerable because of a sickness, and how much someone could resent feeling that way.
Two more days passed, and the sniffles turned into a clogged nose that allowed no air through Tony's nasal passage, and a deep, chest rattling cough that had both Steve and Bruce on edge.
Tony had just dropped his screwdriver when a fit of coughing overcame him for the third time in an hour, and Bruce had had enough. He snatched the screwdriver away when Tony retrieved it, and insinuated himself in between the billionaire and his new bot.
"That's it, Tony. I'm tired of watching you cough and hobble around like you're not sick. We're going upstairs and I'm going to take care of you or I'm going to drag your happy ass to the emergency room and they can deal with you," the scientist threatened.
Tony opened his mouth to protest, but was overtaken by another coughing fit, and Bruce wrapped his arms around Tony's shoulders and led him out of the lab.
He managed to maneuver the billionaire into his room and settle him in the bed the three of them shared, and kissed his forehead gently.
"You stay put, I'm going to make you some soup. Don't even think about sneaking back to the lab either, because Jarvis will tell on you, won't you Jarvis?" Bruce said.
"Quite right, Master Banner," the AI responded, and Tony half-heartedly glared at the ceiling.
"Traitor," he muttered, but he snuggled under the covers, lying on his side in a way Bruce knew he only resorted to when injured or sick.
The doctor made his way to the kitchen and smiled as he met Steve there. "Hey," he said and Steve grinned at him.
"You two come up for air?" he asked jovially over a bowl of…something.
"For a while, yeah. Tony's sick and I've banned him from the lab. I was just about to make him some soup."
Steve's grin was even brighter and he gestured to the covered pot that sat, steaming quietly, on the stove. "I figured today would be the breaking point. I made it special; my mom used to make it for me when I was sick," he said with a soft smile.
Bruce smiled at him and hugged the super soldier around the waist. "Have I told you lately that I love you?" he murmured.
"Yes, but it's always nice to hear," Steve replied and they got a bowl of soup and took it up to Tony. The billionaire complained and vowed that he was fine, but he made no move to escape the warm cocoon the two other men made around him, and didn't even protest when Steve spoon fed him.
Hours later, when the three of them lay together under the covers, Tony spoke. "If I had known getting sick would get me this much attention, I would have done it sooner."
They shared a laugh and a kiss despite Tony's protests of 'No I'll get you sick.'
It was their own personal patch of heaven.