Sticky residue, also know as semen, left above the upper lip of the person who just gave a blow job. The semen dries to give the appearance of a white mustache. Got cum?
A mustache of semen (cum) that is delacately layed on the upper lip of a female, or in a homosexuals case on the upper lip of a man. This can be licked off by any partner and deposited into a sink or swallowed. Make sure there are no STD's while preforming this sexual activity. Best done after oral sex.
Dude i was gettin head from this chick and i cumed on her face and made a cumstache outta it... it was gnarly. it was a true work of art! She swallowed it and everything!
After the act of oral sex, on occasion the partner's cum is left behind on the upper lip, under the nose. This can resemble a mustache and commonly confused as a milk mustache.
John gave the ho a fancy handle-bar cumstache, paid for her fine services and departed ways.