The first time he watches Sam fall asleep, they’re in the stupid tiny car on the autobahn.
Bucky stares at the back of Sam’s head, ignores how cramped his legs are. Watches Sam’s head slowly sink back and sideways until it’s slumped into the gap between the seat and the window. If he triangulates between the wing and rear-view mirrors, Bucky can see Sam’s face, slack with sleep, mouth soft. He wants to look and he doesn’t. He doesn’t know Sam Wilson at all, knows only that he doesn’t trust Bucky - an accurate assessment of Bucky’s threat level, Bucky thinks - and that he does trust Steve (also accurate, although probably stupid). Sam looks vulnerable, like this.