A skin flute is a very special, but not very unique type of flute commonly referred to as a PENIS. Someone who plays the skin flute sucks a lot of cock

A euphemism for “kill me” now that composting oneself after one’s death has become popular.

a gay man's favorite instrument

A one-holed instrument that plays best with quick hand movements and nimble finger placement.

Cock.

an insturment that many people enjoy playing. Combine with a tromboner and a sexaphone and you will have the best band in the land.

A "skin flute" is a lesser known euphemism for a "penis." Use of the term "skin flute" is the mark of an obviously hip, knowledgeable individual.