1)Steve Rogers not showing/admitting the fact he is also attracted to men even after he woke up, because he doesn't want (or think he can handle) to be called a pervert or any other slur. It'll tarnish what he had with Bucky, he'll only be able to remember being scared about their relationship instead of all the happy parts like nose kisses and cuddling. And sex, I guess. When Bucky comes back he doesn't mention it, 'cause he doesn't want to influence Bucky's decision and make him feel obligated
to be in a relationship with Steve that’s more than platonic. Bucky does remember though, eventually, and when he mentions it he’s pretty sure Steve hasn’t said anything about it because he doesn’t want to be like that anymore, now that he’s all healthy he can find a nice girl and he wouldn’t hide around with a scarred up murderer with more issues than National Geographic, /because no one told Bucky it was okay to be gay/. Steve is obviously more than willing for their relationship to bloom again. They’re not hiding their relationship, per say, but they make 0 effort to let people know about this development because it’s so ingrained in them not to let anyone know. They cuddle in public places and kisses on the head and stuff, but they’re /never/ caught making out because that sort of thing is private. They hardly kiss on the lips unless it’s inside on their floor or with people they really truly trust. Unless one of them does something stupid (Steve, let’s be real) and well the other Avengers even go on what is obviously double dates, with Pepper/Tony and/or Clint/Natasha, but they’re not overly affectionate in public and you’d just think they were friends by looking at ‘em. They didn’t tell the Avengers either. Tony just walked in on them cuddling and giggling together and asked if they were, y'know, together, and neither could really say anything so they just nodded their heads and Tony offered his congrats before talking about that arm again.
And it’s not that Steve or Bucky were ashamed of the other, but at the beginning they /knew/ it was legal, but knowing and /knowing/ are two different things and they didn’t want to jeopardize what they had. Modern Day Steve/Bucky is on the down low because it makes them feel safer without their relationship being so open to the “public”. When they get married they sign a piece of paper and that’s the only time they really say out loud that they’re in a relationship together, because it’s
such a momentous, happy occasion that they can break taboo to do it. /the end I’m done now. I just live for low-key Steve/Bucky even in the modern day