Steve had been fantasizing about Tony since day one, hour one, minute one even. He was gorgeous and annoying and lit a fire in Steve that made him want in a way that was as intense now that he loved him as it had been since he hadn't even liked him. There would always be that heat, it wouldn't matter if Tony was seventy five, Steve would always want him.
Eagerness wasn't a fetish exactly, but Steve liked knowing that Tony was enjoying himself. There were some people who got off on pressuring someone and that couldn't have been further from what Steve enjoyed, just call him Steven Enthusiastic Consent Rogers.
It was safe, Steve was him and he couldn't catch something from someone even if they had it but it wasn't something he'd wanted to do with someone before. Before Tony and he suddenly just wanted everything, especially new ways to be closer to him. He withdrew his fingers slowly to wrap his hand around his own dick, adding extra lube. "Are you ready, beautiful?" And he wasn't, not really, but maybe they both needed that a little bit.