Considering just how much Bucky uses his nickname, do you think he ever forgot that his name was James. Like if when he was young someone tried to call him James and he just looked around confused before remembering that his name was James. And maybe Steve would tease him about how he remembered his nickname but not his actual name. And maybe that happened many more times, to the point where in the army they just stop trying to call him James because he kept not responding because he forgot his name wasn’t Bucky. And maybe after reuniting with Steve after being the Winter Soldier, Bucky told Steve that the teasing was correct, because even when he forgot everything else, he never truly forgot the nickname, because Steve was the one who gave him.
I apologise for derailing your sweet bunny with smut and bamfery no I don't but may I also offer:
'Bucky' is such an everyday thing for Steve and Bucky that Bucky actually likes to get Steve to cry his legal name when Bucky makes him cum because it feels ~Spicy coming from Steve.
Or: Super-popular 'constantly beset by ppl wanting to fuck me' prewar Bucky introducing himself as 'James' to people he doesn't intend to see again after that one night, so that if anyone he vaguely recognises calls out to him as 'James!' in the street, he can immediately clock that it's one of Them, and has a chance to wrack his brain to remember which club and which night he knows them from before he greets them back.
And also: Someone personally betraying Bucky and calling out to him by his nickname as he walks away and Bucky stops, lifts them up by the throat, pulls them in close for a murder-glare, and says 'No. Bucky is for friends and family. To you... my name is James.'














