When one farts while sitting and the escaping gasses cause one's testicles to move. (Can also be accomplished while standing, but one's testes must be hanging low.)

When you fart in the bathtub and bite the bubbles.

Good old resonated pot, the resin you get from smoking large amounts of weed out of a pipe/bowl. thought to originate from central pennsylvania (Penn State Unvi)

The act of sitting in the tub and farting, and trying to eat the bubbles before they pop.

one who farts in a tub and smells the bubbles

Aperson who bites the fart bubbles in the tub.

an individual who eats fart bubbles out of the tub and frequently sniffs bicycle seats.