1) When a man and woman engage in sexual intercourse, generally in a dog-like position (doggy style
), the man, while laying the bone
, proceeds to insert his index and middle finger into said womans anus
. Upon the removal of the fingers, the man proceeds to whipe the fecal residue on the womans upper lip. The look of the woman is one of utter disgust, resulting in her looking like a dirty mexican named Sanchez. Hence, the name Dirty Sanchez
2) A disgustingly unkempt moustache, that actually looks like it's made of shit
DISCLAIMER: IF YOU ATTEMPT THIS, THE SHIT MAY BURN HER LIP. USE EXTREME CAUTION.