I have this headcanon like can u imagine tony being the only person who can fix bucky ahhhhh
I have a headcanon that Bucky latches on to Tony for whatever reason (maybe because he’s a fucking good human being who doesn’t treat Bucky like he’s fragile. Like he’s broken. but whatever) and Tony becomes the only one Bucky will even let try and help him.
He becomes the one Bucky goes to when he needs comforting- no empty words about how it will all be okay in time, about how nothing was his fault and he shouldn’t feel bad- just a warm presence and a quiet one sided conversation about mundane things like board meetings and suit upgrades.
Occasionally, Tony would let his hand fall near Bucky’s. A no-pressure invitation- which Bucky usually ended up taking more often that not.
He’s the one Bucky goes to about his arm- no matter what Steve and Sam say about seeing ‘proper’ specialists, there is no way on hell or Earth that he’d let a stranger fiddle about with those mechanisms. He’d end up killing them without even blinking- the arm is… sensitive. And no-one he doesn’t explicitly, fully trust is going near it.
And eventually, he learns how to trust others. Tony lets him realise how much his behaviour is affecting Steve, who just wants to help him, and Bucky hates thinking that he is hurting more people. Again.
So he lets go a little. Allows other people in. Learns everything all over- how to be human, how to be kind. It’s difficult- so very difficult- but he makes it, in the end. He comes out the other side.
He still sticks with Tony, though. Because Tony was the first. And Tony was twisted and broken and completely, utterly amazing.
( and God forbid if you hurt him in any way while Bucky was around. Winter Solider aggression mixed with Bucky Barnes protectiveness?? Holy shit you’d better run.)