A/N: Written for the prompt: Tony and Steve are bros, and they just don't know it. One of these days, I'm writing a fic longer than 500 words. Promise. Promise.

There's a lot of things about Tony Stark that irritates Steve Rogers.

To be frank, there's a lot of things about Tony Stark that irritates everyone. It ranges from faint annoyance to outright murder, and Steve often wonders how the others are able to keep their desire to throw Stark out a window in check.

He's arrogant. Steve has never been able to tolerate that particular trait. Even Bucky, who had a good dose of cockiness, knew to keep his ego in check around Steve, because, in Steve's humble opinion, nothing tears a mission apart faster than a guy with arrogance.

He's rude. There's no boundaries with Stark, no cut-off line. Anything and everything is open game for him, and he makes a joke out of every topic, no matter how taboo it is. Bruce turning into the Hulk? That's one of his favourite topics, and nothing bothers Steve more than to see Tony poking and prodding Bruce with various triggers. As if the Hulk is a toy. As if he wants a repeat of what happened the last time they lost control.

He's got problems with authority. Tony Stark doesn't like being told what to do, and he doesn't like the implication that there are people who know more than he does. He constantly rubs Fury and Steve the wrong way, testing the limits — often, trampling right over them — and while he never assumes complete control of the Avengers, he often undermines Steve in the smallest things. He acts without thinking, jumps into the fray before there's a plan, puts himself in danger because he can't sit still.

In all honesty, Steve should hate the guy. If Steve knew how to hate, he would. But even if he could, he can't.

He understands Tony.

There's arrogance, and a stupid sense of humor, and danger, yes. There's also that tenderness for Pepper Potts, that friendship with Bruce that no one else can match, that focus that settles over him when he works on something.

Tony might have the attention span of a goldfish, but when he puts his mind to something … well, who else could have made a war machine out of spare parts in the middle of the desert?

He's ready to sacrifice himself at a moment's notice, and it's not even because he's trying to be a hero. It just makes sense. If he had stopped to think, maybe he could have found a way to deflect the nuclear missile without nearly killing himself. But that's not Tony's style. Stopping to think wastes time. His actions saved a million lives. It's not rocket science to Tony.

He cares a lot more than he lets on. He feels a lot harder than he'll ever admit. He hides behind the arrogance and the jokes because he thinks that Steve is right. Without the suit, Tony is nothing. Just another rich boy with daddy issues.

He's one of the most important members of the team, whether Steve likes it or not.

And although it kills Steve to admit it, he doesn't mind Tony's presence all that much anymore.