A term used to refer to someone who is so obese that their enormous ass is too large to fit in one seat, and must therefore occupy two, usually achieved by awkwardly straddling the armrest. This person is considered to be wearing an armrest thong. See also: Assassination
Obese man: Do you have anymore seats available for this flight?
Receptionist: We do... but you'll have to wear an armrest thong.
Guy: This armrest smells like ass!
Stewardess: Al Roker was sitting there the last trip.
Guy: In which seat?