An acronym that stands for Bitch Over Shoulder Sightseeing. Used when your parents/siblings have figured out what POS means. Especially useful because of it's alternate definition.
aimfriend: So yeah, at the party last night, how many beers did you..
aimyou: yeah it was BOSS, man!
aimfriend: Oh, right.. Um, yeah, what was the algebra homework again?