What is Dirty Fu Man Chu?
1.
Very similar to a Dirty Sanchez - Reaming a chick from behind (doggy-style) and then rimming her asshole with two fingers with which you run it (fecal matter and all) under her nose as to make a moustache with one finger, while the other shit-covered finger runs under her lower lip. Then, you rim the girl's ass again, and this time, you run both fingers down the side of her mouth down to her chin, making the girl look like a Kung Fu star.
I couldn't stop laughing after I gave your sister a dirty Fu Man Chu - she looked like she liked it.
See
