He is! I get the feeling that Tony no longer has to sleep except when he's wounded, which means he can get all those "stuck indoors doing paperwork/designing things that go boom/being responsible" things out of the way, and then have all night to enjoy fresh air and open sky and semi-public sex with Steve the like. So Steve can sleep while Tony works. It's very convenient.

He can insist on unsexy places. Inner elbow. Wrists. Not ankles, because then Tony would probably say something about a foot fetish and Steve would have to make everyone in New York stop painting their toenails. Tony would enjoy teasing him about it—dancing around the topic in faux innocent confusion and inwardly gleeful that Steve's face is only a few shades away from matching his armor.