The type of fart where a little bit of non-gas comes out, necessitating a change of knickers. While the idea of getting something extra or "value-added" is generally an attractive proposition, in this case it emphatically is not, because the "plus" you get is shit.

There are many important reasons not to wear white pants but this is pretty high up there.

A casual invitation / threat used by an individual that is not afraid of fucking someone up.