A part of Steve could understand the burden of keeping something inside, but not that it had to bubble out to the person involved. If Tony needed to talk, but he didn't actually want anything to change between them, then why not talk to one of the others? Vent his feelings until they disappeared, if that's what he was waiting for.

"Okay, so now I know."

He still kept his voice level, because even if he was kind of frustrated with how Tony was choosing to go about this, he wasn't going to be angry at someone for what they couldn't help feeling.

"But if all you wanted to do is tell me, then I'm not really sure where to go from here."