This could've gone better.

bucky is well aware donnie doesn't see or want him as a father figure, but he still wants to be at least someone donnie can TRUST, and that's what he thinks donnie is constantly rejecting lol

meanwhile donnie takes the "I want to be here for you" as "I'M PARENTING" which for someone with Bucky's super strong nesting instinct, is not a bad assumption lol

yeeeeep

it also wasn't helped that Donnie's intro to Bucky was "This is dad" so some of it can be blamed on Leo.

bucky is considering cornering him under the table at the wedding though lol

do it

he can't flee without making a scene, which he wouldn't want to do.