WS Bucky was kept in chastity any time he was out of cryo. Insert your preferred reason here, like maybe it was a way to control him and make sure he didn't get distracted by getting hard, they didn't want him fucking anyone, it was one of Pierce's twisted little games, or whatever. Since he wasn't given the chance to get hard they'd just milk his prostrate to drain his balls. This made him really sensitive to prostate stimulation which leads me to: I want the aftermath of this with Steve. Bucky can't get it up but he can come, and come hard, by getting fucked. Maybe Steve gets off on how soft Bucky stays while Steve fucks him and he feels terrible because he knows how much the whole thing bothers Bucky. I will be an extra happy dumpster camper if you have Steve fondling Bucky's flaccid cock while he gets him off or fucks him.