Loved like a brother. It's that which gets Tony's focus, nothing else. He reminds Steve of someone he cares deeply about. And sure, fine, there are other, better people. There are people more suited to the life of a solider and even people better at being friends. And yet--

"Cap."

He doesn't want to sit here. And he doesn't want to listen any more. Listening just makes all of it worse. 

"Thanks. I think. Are you going to be all right if I go and pass out?"

Or more likely rub one out. 

Alone. Very alone. 

Watching those pale pink lips has done terrible things to him. Tony isn't really a bad man. 

He's just not as good a one as the man Steve lost.