It's an accident, really. There's honestly no way Steve could have planned this, anyway.
It happens in the kitchen.
Steve's pretty comfortable with his teammates, sure. He doesn't see them all that much, considering he sticks to his floor when he's in the Tower. He's had some concepts of bonding and meshing together rolling around in the back of his head, but he has yet to deal with that. No one's openly hostile to another team member yet, so it's okay for now.
But yeah, he's comfortable with his teammates. He says good morning as he passes them on the way to grab something to eat, and it's alright. He trusts them all well enough.
But then in comes Pepper.
And it's not that he doesn't trust Pepper, no. She hasn't done he should resent, as far as he knows, and Tony trusts her, so. That's that.
He's still not fully awake though, and he really is still groggy, and ok, fine, he does get nervous around women. Sue him.
So he just watches, quietly, from the island where he's buttering his toast. Pepper makes her rounds, passing Tony some papers and squeezing his arm, hugging Natasha and calling out greetings to the rest of them.
She smiles when she gets to Steve. “Good morning, Steve. How’re you doing?” she asks calmly, reaching for a peach from the bowl on the counter.
And Steve just- he panics, ok? He thinks I'm good but is he really and I'm okay but that sounds sad and oh wait she's still looking at him and he hasn't answered and-
“I'm gay.” he blurts out, happy to finally get some words out, and then he realizes what he said, and oh god.
Pepper stands there, frozen for a moment, poised to take a bite of her peach. She slowly lowers it from her mouth, but her mouth doesn't close, which is shocking when you consider her normal level of composure.
“Steve,” she says, in a really soft tone that he doesn't need because really, he's not actually gay, he just misspoke, he's never even been attracted to a guy an-
He starts sputtering something to the accord when he's caught off by a loud whoop from Clint. “I knew it! Didn't I tell you! Nat,” he says, turning towards her. “didn't I tell you? I said, there's a whole bunch of hot guys on this team, there's no way some of us haven't discovered we're not straight, Nat, didn't I tell you!”
She pats his arm, consolingly. “You're on this team too, idiot. And you spend more time talking about the hot guys on this team than any of the others do.”
Clint eyes widen. “Well, damn,” he says calmly, and then he shrugs. He turns, and fist bumps Steve on his way out. “Awesome, bro.” is all he says.
Whatever it was that had just happened distracts Steve enough that for a second he doesn't remember that he's supposed to be telling them he's straight, but then Pepper and Nat are both patting his arms and congratulating him and then they're off, to somewhere, he doesn't know, and that's three people he's let walk out the room thinking he's gay when he's not, and he knows it's okay now but that's not the problem, he just isn't gay.
That's when he notices that Tony is suddenly a lot closer than he had been a few moments ago, which was confusing, but at least he could tell Tony he was straight, and Tony would make sure the others knew, this would be cleaned up so quickly-
“I am too, you know,” Tony says, and Steve can hear the barely hidden barely hidden excitement in Tony’s voice, but he doesn't know why, and oh.
Steve suddenly feels terrible, really, genuinely terrible, because Tony’s coming out to him misinformed, and god, if he'd just shut up for a second-
“-probably picked up on that already, anyway. Yeah. Cool. I think it's cool, don't you? Anyway, I totally get how you're feeling. Or maybe not, individual experiences and the like. We could find out, though. Or not. It's cool.”
“Tony… I, I'm not..”
Tony won't even let him get a word in edgewise. “No, no, Steve it's okay. You don't need to panic, no panicking necessary. Ok, maybe you should panic about the way you came out, because I think you broke Clint, but that alright, no one will even notice the difference, you can come out whatever way you want, it's fine-”
“TONY.” Steve says loudly, trying to get his attention. “I'm not gay.”
Tony stops. He listens. And then his makes this heartbreakingly sad face and what the fuck is he making cooing noises?
“No Steve, it's ok, you don't need to tell you self that again, it ok, lying to yourself isn't worth it, trust me, I tried it for years, it doesn't work-”
And what the fuck is Steve supposed to do in the face of that? Tony’s practically baring his soul here, and Steve shouldn't be hearing any of this.
“Tony, no, I'm attracted to women.” He says firmly. There's no way for him to misinterpret that.
“That's alright, too, lots of people use gay as an umbrella term, Steve, you can call yourself gay, or bisexual, or maybe pan, or go without a label, it doesn't really matter, it's no one's business anyway.”
“Tony-” he says, really, why was it so fucking hard to get his point across, but Tony just won't stop.
“Hey,” Tony says suddenly, “You should celebrate. Wanna go out to dinner? Dinner's good, could be fancy, could be casual. Or, I mean, we could do a team dinner, or I know a whole bunch of guys, I can set you up easily, just name your type, but you don't have to, no pressure…”
“Tony,” Steve says, for what has to be the hundredth time.
“Oh, what's that?” Tony throws a grin at him. “Your type is ‘Tony’? You have great taste, you know, no, I'm teasing you, don't sweat it, but seriously... dinner, just me and you?”
It's all Steve can do to nod. He's not even sure what he agreed to, really, Tony’s steamrolling on to something else now.
He'll think of a way to tell them all before his dinner - date? - thing with Tony.
He ended up telling Tony somewhere around their fourth anniversary. Tony wouldn't stop laughing for the rest of the day.