"We should get married."
Tony still isn't entirely sure where that one had come from to this day. It had seemed like a fantastic idea at the time, not that he was really regretting it now. The fact that Steve didn't argue was pretty telling on his thoughts of the matter, considering, unlike Tony, he wasn't rip-roaring drunk at the time.
Steve froze, awkward smile stretched across his face. "What?"
"We should get married!" Tony raised his glass as if in toast, almost spilling half of it on the floor. "It's a great idea, probably like the best I've ever had."
"And why exactly should we get married?" Steve's face had turned serious, an eyebrow quirked almost like he was seriously thinking this through. Which, at the time, Tony had not been.
"Because," Tony said suddenly serious, "tomorrow we're going to fight a giant evil fucking robot, who hates my guts probably more than anything in the world, and we all might die. Therefore we should get married."
Steve snorted, though he looked unamused. "I'm still not seeing the logic behind that one, Tony."
Tony looked down at the glass in his hand, suddenly sad looking.
"Look, Cap, I know we don't necessarily get along all the time. But being perfectly honest, you're probably one of my closest friends right now, besides Bruce. And I like you. A lot. Like, a lot, a lot. And if I die tomorrow I want to die knowing I made a move like I wanted to. And if you die and I somehow survive," Tony's breath hitched, eyes going misty as an image of a broken shield and watching light fade from bright blue eyes under dirty, bloody blonde hair.
"And if you die and I survive, I don't want to spend the rest of my life thinking 'what ifs.' I want... I need to know that I didn't let my chance slip away."
When Tony finally looked back up at Steve, his breath caught. This man he had resented and yet admired all his life, right in front of him, blue eyes blown wide and watery, a single tear trail down his face. As he looked at the way Steve's eyebrown furrowed in thought and little worry lines appeared on his forehead, the way his lips curved down when he was thinking hard, his dimples that only appeared when he clenched his jaw or smiled impossibly wide, eyes bluer than any sky or any tropical ocean he'd ever seen, he couldn't think of anyone he wanted to spend the rest of his time with more. What little time either of them might have left.
Steve took a deep, shaking breath. "Well, you make a compelling argument, I'll give you that," he looked around the room, jaw muscles clenched as he tried to keep his composure.
"Tony, I like you a lot too, and I would love to give this, give us a chance, but I don't know if now is the right ti-"
Tony had reached across the table and grabbed Steve's hand, alcohol forgotten. "Please, Steve? If Ultron kills us all tomorrow, I want to go out knowing I at least took a chance. I might love you, I might not, I don't know. But I want to at least try to find out. Before it's too late."
Tears were leaking out of both of their eyes now, and neither of them made any move to wipe them away. Steve took a few deep, calming breaths. Tony never let go of his hand.
"Okay. Let's get married."
Finding someone to marry them wasn't as difficult as they had thought it would be. Fury had dropped by the tower to meet the twins and Vision and had yet to leave, but thankfully they caught him right before he did.
"You want me to do what now!?"
"Come on, Nick," Tony said, still gripping Steve's hand as if his life depended on it. Maybe he was too afraid to let go, but Steve wasn't exactly arguing so he went along with it. "Just do it, you can question us about it later. We just... we need this."
Fury looked down at their interlocked hands, expression unreadable, and sighed.
"Fine, I'll do it. And I won't tell anyone. But if we all make it out of this alive, we are going to have a serious conversation.'
And that was that. They married in Tony's lab, just him, Steve, and Fury. They didn't wear anything special, no vows were exchanged, because what did you promise to the person you're marrying when you both know there's a good chance one or both of you could be dead in twenty-four hours.
No flowers, no fancy words: just three people, a couple of 'I do's and a kiss, a first kiss, and that was that.
They didn't tell anyone until a while after the fight. Everyone was shocked, of course, but no one argued with them. And that was that. Life went on as normal. Or as close to normal can get when Iron Man and Captain America are semi-happily married to each other.
And that night, after the wedding, they went back to Tony's room to find solace in each other. Sure, they probably needed the sleep for the 'fight-to-end-all' tomorrow, but neither of them much cared. Neither of them got much sleep that night, but in the morning when they left to save the world, neither of them regretted it either.