People love calling Sam baby, sometimes it's to scare him or make him feel small like if Lucifer is chasing him down he'll say "cmon baby don't hide from me" or if Dean walks by him while he'd reading he'll say "hey baby, you should rest soon" while petting his hair, Rowena does it teasingly, if Sam doesn't understand something about a spell she'd go "aweee don't you worry your pretty little head about that baby" Gabriel is no different, he'll say ut the most "hey baby" "what's going on babe" any variation of baby, baby boy, baby girl, babe, babes, he's everyone's baby