Sorry, anon, I like your ideas but not for this prompt. I might have been confusing when I mentioned BDSM in the prompt. What I meant for their relationship is like, Steve is a bottom, and he likes it a little rough (emphasis on a little, bruises and hickeys and the occasional hands held behind back + slap on the ass combo okay, full on spanking + name calling + serious use of "yes sir" not okay), and he gets off on Bucky being bigger. By manhandled I mean Bucky is strong enough to pick him up, or pin him down on the bed. Dirty talk is optional, but I'd prefer it along the lines of what you mentioned, actually, praise like "fuck, doll, you take it so good". So it wouldn't be anything Bucky might have a problem with post HYDRA, in fact, he would be eager to do it because it's what they liked before and also because it's so different from what they did to him.
And then during the rape they end up making Steve's kinks into triggers: Steve likes Bucky pushing him down X they hold him down and he can't fight back, Steve likes being smaller than Bucky X they tell him he is weak and not a real man, Steve likes being fucked X being slutshamed for it (bonus forced orgasm), Bucky's praise of how he is so delicate and pretty X teasing about it.
I wouldn't like it for punishment kink to be involved in their relationship. What Steve really wants is for Bucky to hold him and pet him and fuck him, and Bucky wants to do that for him, but whenever he tries Steve remembers how they made him feel dirty for wanting those things. So he thinks what he should want, as a real man, is to fuck Bucky (like those people that go "It's not gay if I don't take it up the ass"), except he doesn't, and Bucky doesn't particularly want it either, both because it's not his preference and because he is dealing with his own rape, and he doesn't want to do to Bucky something that in his mind is wrong and humiliating. Cue disastrous sex attempts that end up with either or both of them curled up into balls of self-loathing / semi-successful sex where Bucky is good but Steve is a curled up ball of self-loathing for getting off on the things he is not supposed to.
Re: Steve thinks he is wrong for liking to bottom
And then during the rape they end up making Steve's kinks into triggers: Steve likes Bucky pushing him down X they hold him down and he can't fight back, Steve likes being smaller than Bucky X they tell him he is weak and not a real man, Steve likes being fucked X being slutshamed for it (bonus forced orgasm), Bucky's praise of how he is so delicate and pretty X teasing about it.
I wouldn't like it for punishment kink to be involved in their relationship. What Steve really wants is for Bucky to hold him and pet him and fuck him, and Bucky wants to do that for him, but whenever he tries Steve remembers how they made him feel dirty for wanting those things. So he thinks what he should want, as a real man, is to fuck Bucky (like those people that go "It's not gay if I don't take it up the ass"), except he doesn't, and Bucky doesn't particularly want it either, both because it's not his preference and because he is dealing with his own rape, and he doesn't want to do to Bucky something that in his mind is wrong and humiliating. Cue disastrous sex attempts that end up with either or both of them curled up into balls of self-loathing / semi-successful sex where Bucky is good but Steve is a curled up ball of self-loathing for getting off on the things he is not supposed to.