The act of engaging in the doggy style position then fingering
the female's anus while in that position and
smearing a residue of her own shit accross her
upper lip forming a mustache.
*Dan walks up to Mark*
Dan: Hey Mark,
you remember that crazy guy on the bus that was masturbating?
Mark: Yeah man, it was
fucking sick.
Dan: Yeah, well you wanna know what his name was?
Mark: What?
Dan: Sanchez!
*Dan smears shit over
Mark's upper lip, leaving a shit moustache (a dirty sanchez)*