fart-boxers

A pair of boxers that a boy keeps in his room and never washes. These are usually his prized possession in his messy room / closet. They usually smell like the boy's farts, since he would have done so in them many times before.

boy 1: what are these?
boy 2: my fart-boxers, they're always lying around here.
boy 1: oh, nice man; mine are blue.