Bloody Mustache 

When a guy (with a mustache) goes down on a girl and she has/gets her period while he's eating her out causing the residue to get on his stache.

Guy #1: Freddy ate Jenny out last night.
Guy #2: How do you know?
Guy #1: He came out with a Bloody Mustache.
Guy #2: That's just ... wonderful.

Bloody Mustache by Adrianaaaaaaaaa. December 12, 2010

blood mustache 

the ring of period blood around the mouth of a female, especially noticeable on the upper lip; most commonly left after having vaginal intercourse while the female is menstruating and then pulling out prior to ejaculation in the female’s mouth, leaving a “blood mustache.”

She told me to pull out so I could cum in her mouth and I gave her a blood mustache.

blood mustache by Marty Farrington July 17, 2007

Bloody Moustache 

When one receives a bloody lining around their lips, particularly the upper lip, as a result of performing oral sex on a woman while she is menstruating.

I wish my girlfriend would get off her fucking period. She keeps giving me bloody moustaches and I don't appreciate it one bit!!!

Bloody Moustache by Lindley! May 18, 2009