Bucky expects guards and guns, maybe a fight. He keeps his seat even as the door opens, ready to spring up if needed but trying to hold himself in check.
There’s two sets of footsteps, and then Bucky looks to his left where they stop.
It’s a guard, all right. And next to him, still in his uniform, is Buck. He’s bruised and busted, though not as badly as Bucky. He’s standing at ease, like he’s not shocked to see Bucky.
But Buck looks not shocked to people who don’t know him a lot of the time. Bucky, though, he can read that face like his favorite book. And Buck’s face is stoic, but there’s mayhem in his eyes.
Source: A Daring Escape, by Perpetual Motion (perpetfic) – Masters of the Air (TV 2024) [Archive of Our Own]
Teen, canon divergence, established relationship. I wish this was longer, but I have a serious competence kink, and there’s something delicious to Bucky and Buck being all “efficient and stabby” when killing Nazis, as the tags on AO3 say. 
Also, background polyamory mention.