Big Louie
A generic phrase to describe any sexually transmitted disease, or as a shorthand to describe having multiple STDs. Some dispute exists as to the proper spelling, but either "Big Louie" or "Big Louis" is acceptable.
Dude, if a chick ever makes you get tested for the Big Louie, make sure to piss in the cup instead of letting them stick that huge q-tip in there, that shit hurts.