ketchup moustache Share definition Flag When a person performs oral sex on a girl who is on her period. Also called "catsup moustache" in some areas "Hey your mom is cool. She gave me some cookies and a ketchup moustache." "Yea... what?" ketchup moustache by A.C. SlayinPussy July 20, 2016 0 0 Get merch Get the ketchup moustache mug. Buy Now — $32.95 See more merch