This work could have adult content. If you proceed you have agreed that you are willing to see such content.
He knows what he’s going to do next is far beyond the realm of ‘appropriate things teammates to do one another’, but it’s not like the Avengers are known for how professional they are. Also, the point of this whole thing is to make Steve give up. It’s irrelevant whether he does it because he can’t continue anymore, or because he has to push Tony off him.
Basically a fic where Tony lies down on top of Steve, chest to back, and gives Steve a hand job while the latter does push-ups.