It's obvious, when Steve stops to think about it.
Tony always seems overly close with his bodyguard. Whenever they talk about each other, it's like they have their own little private joke, saying each other's names pointedly, laughingly. When Iron Man is in the same room as Tony, he stands close, sometimes pressing his metal shoulder into Tony's.
Which- hey, good for them, is Steve's opinion. He wishes them all the happiness in the world, or as much as a superhero and an ex-arms dealer can get.
It really is how Steve feels, except Steve's persistent little crush on both of them that refuses to budge.
It makes Steve feel guilty whenever he thinks about it- not only are both of them men his close friends, but they're dating each other. There's no way Steve could get between that.
Or, well. There is, but whenever he thinks about that his neck gets hot and his pants get too tight and he quickly switches subjects to something a little safer, like smashing doombots.
Those thoughts are quickly wiped from Steve's mind when they haul Iron Man out of a wrecked building and get his helmet off, and Steve is met with the all-too-familiar face of Tony Stark.
That- that makes less sense than Steve's boyfriend theory.
They're stuck waiting for Tony- Iron Man- to wake up, and when he does, he says, "Hey, wh-" and then freezes, probably due to how un-modified his voice is coming out.
His hands go to his face, gauntlets touching skin, and Tony pales. "Cap-"
"Hey, Shellhead," Steve says, trying to keep his voice even. "Good to see you awake."
Tony wets his lips. "I'm sorry you had to find out like this," he says, low and honest and painkiller-hazy. His gauntlets clench and open around nothing, a nervous tick of Tony's, and god, Steve should have seen it sooner.
The gauntlets still when Steve takes one of them in his hand. "I'm just glad you're okay. I, uh, always assumed Iron Man had some kind of healing ability, he was always up so quickly after getting knocked down."
Tony's grin is genuine, if not a bit uneasy. "Just me, Cap."
"Mm," Steve says. "In that case, you're definitely getting checked out by medical more often, mister."
Tony's face falls. "I'm-"
"I've seen your medical records, you're not fine."
Tony makes a face. "Your mother-henning is going to be on overdrive from now on, huh."
"You bet," Steve agrees. He swallows. "Hey, when Iron Man was in the same room as you, was- I mean, did you get someone else-"
"Empty suit," Tony sighs. "I controlled it with a tablet in my pocket. Steve, you okay?"
Steve clears his throat. He might have made a small noise. "You're the one in the hospital bed, Shellhead."
"Do not say you're fine," Steve warns, and he gets an eyeroll in return.
Tony starts talking, and Steve nods along and tells himself it would be incredibly inappropriate to get aroused in a hospital ward next to your best friend. Friends, since Tony is both Tony Stark and Iron Man.
Steve is not at all turned on by that, no sir.
He manages to keep up that facade until late next week, after Tony has been checked out of hospital and starts walking around in his Iron Man armor with his helmet off.
Steve is coping, he's handling this, and maybe once or twice he has to run to the bathroom to jerk off when he thinks about it too hard, but other than that, everything's fine.
This all gets blown to hell when Tony squeezes Steve's shoulder with a gauntlet after sparring in the armor, and Steve groans, breathless and needy.
It's not loud, but both of them freeze at the sound. With his helmet off now, Steve can see Tony's wide eyes.
"Uh," Steve says, hoping Tony will excuse his blush as a result of working out. "Sorry. That, uh, felt good."
Why, his brain screams at him unhelpfully. You groaned, you moron, he knows it felt good because you groaned.
"Uh-huh," Tony says, only slightly hesitant. And then the cocky grin is back, blazing. "What, you got a few knots you need worked out, Cap? I could lend you a hand, if you need it."
DON'T DO IT, YOU'LL GROAN AGAIN, his brain warns him, and then wails when Steve hears himself say, "That'd be swell, thanks."
Tony nods, comes to move behind Steve. "Deep breaths," he says, and then his metal fingers are massaging Steve's shoulders, shifting down his back, thumbs pressing inwards.
Steve bites his lip against another groan. It's official, he's done for. There is no return from this, Tony's fingers are unknotting his back and getting him hard enough to hammer nails at the same time.
As he wills his stubborn (inappropriate, stupid) erection to go the hell back down, Tony says, "God, you have a lot of tension in your back."
It's from resisting the urge to jump on you, Steve doesn't say. "Pressures of the job."
"Yeah, upholding America's ideals must weigh on a man."
Steve huffs a laugh, and Tony's hands move back up to his shoulders, pressing.
"A lot of tension here, too," he says, and Steve thinks he's frowning. "You gotta relax more, Cap."
"Says you," Steve says weakly, and Tony laughs.
"Okay, workaholic, you got me there." Tony's frowning again, Steve can hear it in his voice. "This would be easier if-"
He's still talking when he turns Steve around, and Steve, who had started to relax seconds earlier, lets him before remembering a split second later.
Tony's words tamper off when he catches the panic in Steve's eyes, and then follow Steve's panicked glance downwards to see Steve's unfortunate erection pressing up against the armor, which- okay, Steve can't not whimper at the feel of it against him, hating the noise even as it passes his lips.
"Sorry," he croaks, already backing away. "God, Tony, I never-"
Tony's hand on his shoulder stops him, and Steve brushes it off.
"What for," Tony asks, getting in his space, and Steve stops just so Tony doesn't touch him with the armor.
"For- getting, uh. Aroused, while you- I don't want to make you uncomfortable," Steve says miserably, still irritatingly hard despite everything.
Tony is staring, and Steve can't decipher his expression. "Before, when I squeezed your shoulder, you- liked that?" He pauses, gauntleted hands clenching and unclenching on air. "The armor?"
"You in the armor," Steve says, deciding he might as well be honest now. "And- well out of the armor, and the armor, too, uh, Iron Man, too."
Tony hasn't blinked since Steve started speaking. It's kind of creepy. "You like me."
Steve only hesitates for a moment. "I do."
"And Iron Man."
"And Iron Man," Steve says, nodding, a short, quick incline of his head, his jaw stiff. "I thought- I didn't know he was you, and finding out the guy in the suit was you, it-"
Tony moves, and Steve braces for a punch and gets a kiss instead.
He doesn't kiss back for a few seconds, too surprised, but then Tony's metal hands come up to grip in Steve's hair and all of Steve's senses come back on overdrive. He moans, bringing his hands up to grasp Tony's upper arms, the metal warm under his skin.
"You like Iron Man," Tony says, grinning distractedly when they pull apart. His fingers tighten in Steve's hair, making him gasp.
"I like the guy in the armor," Steve says, trying to chase Tony's mouth, but Tony leans back.
"Yeah, but you like that, too, huh," Tony says, grin wide and cocky and hungry. "I've never been with anyone who was as enthusiastic about it as I am."
He pushes an amored leg in between Steve's thighs, and Steve can't stop making sounds, desperate, pitches moans as he rubs against the metal. "Tony, Shellhead, oh-"
Tony hums into his mouth, bites at his bottom lip. "We are so exploring this, Steve, I'll design something, I'll build a suit to wear just for fucking you, we can do it right in the workshop-"
Steve gasps, "Iron Man," and comes, loud and embarrassing, and by the end of it he's sagging against the armor, which can easily hold him up.
"I can't believe I made you cream your pants," Tony muses, and Steve slurs something into his neck, kisses the skin there, then the metal that starts underneath his collar.
Tony kisses his hair, and asks, "Mind if we move this to the bedroom? I've read your medical files, Cap, and I know you're fully capable of going four or five times, and I'm kind of dying here." He taps the groin of the suit, and Steve frowns.
"Doesn't that hurt? Getting aroused in the armor?"
"So much," Tony says, dragging Steve towards the elevator. "It hurts, Steve, save me from the pain-"
"Drama queen," Steve says, and Tony makes a laugh that turns into a groan when Steve starts fumbling at the clasp of his groin plate.