look up any word, like cleveland steamer:
 
1.
a sexual act where one fingers one's partner's anus and then gives oneself or one's partner a mustache with the filthy finger
That Jessica's such a slut - she's given half the boys in school a filthy sanchez.
by Sanchez August 13, 2004
 
2.
1. the sexual act of following anal sex immediately with oral sex, which causes residual fecal matter to coagulate on the recipient's upper lip, resembling a Mexican handlebar moustache

2. Unexplained sexual position taught by South Park character Mr. Garrison to his kindergarten class.
(1) 'Naw, I gave that slut Jessica a Filthy Sanchez, dude, not the other way around!'
(2) 'Ike, do you know what a "Filthy Sanchez" is?'
by 1337 d00d July 01, 2005
 
3.
Receiving oral sex while taking a shit on the toilet.
This slut at the taqueria follwed me into the restroom and give me a filthy sanchez.
by Zrabbit August 10, 2005