When Steve and Bucky finally do reunite, Bucky has gotten hit by the whump stick so hard it broke, then they went to the back to get another. Metal arm torn off, broken bones, dislocations, burns, starvation/exposure, whatever your sad little garbage heart desires. Bucky needs a lot of attention and at first he's really not happy about it. Extra points if he needs help eating and bathing, at least at the start, so he's really helpless.

But Bucky finds he really, really likes Steve taking care of him. It's a huge contrast from the way he was used to being treated, and Steve is very affectionate and keeps reassuring Bucky that he's safe. Maybe there's a comforting aspect to knowing that he can't hurt Steve if his programming is triggered. And Steve is clearly happy, even tells Bucky that he's happy, to repay him for all the times Bucky took care of him in the past.

So Bucky is not at all eager to get better, and sneakily sabotages or denies his own recovery so he can get more attention from Steve. Steve would of course be oblivious, and probably unintentionally enabling, because of Bucky's initial reluctance.

Extra bonus if Natasha and/or Sam realize what's going on, but are not sure if they should call him out on it. Maybe they argue about it.