Taken from Duece Bigalow European Gigalo. Since it is based off of the Dirty Sanchez when you make a mustache effect. The Filthy Lopez is when you engage in anal sex then make a full goti and sideburns.

A pubic hair piece. A toupee for the pubic area/genitals. In the 1700’s when mercury was used to treat sexually transmitted diseases (Gonorrhea or Syphilis) one of the side effects was the loss of pubic hair. To disguise this condition, that was not cured by mercury, a Merkin was employed.

A "Filthy Lopez" is a "Dirty Sanchez" add the sideburns.

About forty bucks. Same as downtown.

A "Filthy Lopez" is a Portuguese equivalent of the more common Dirty Sanchez.
A considerable degree smuttier than its Mexican cousin a "Filthy Lopez" additionally involves the use of Peri Peri sauce in the Dirty Sanchez act.

Used in the movie Deuce Bigelow 2 as a euphamism for a sexual act. The act is never defined, but I would assume it is a funny modification of the term "Dirty Sanchez."