rewatched the last two episodes and noticed how Bucky tries to keep a respectful distance btw him and Sam whenever they're beside each other, petting his back/shoulders with only one hand, arm stretched out completely and head down, looking away.
while Sam just simply lets his own arms, shoulders or elbows practically touch Bucky's, keeping himself near his old man and not caring at all about personal space, maintaining eye contact, smiling from ear to ear, pulling him closer, touching Bucky like somehow they've been doing it since forever.