The grossest(could be a word) porno I ever saw was this one called, Ass, Gas, and the Mystical Glop. My onetime roomate Joe, who was shamelessly addicted to porno rented it one night
The whole deal was that these 4 guy all went in the back door on this girl, and then another girl sucks it out of her butt with a fairly large straw.
After I saw this anytime I heard the slurping noise made my a straw it imediately caused gagging and often times throwing up