skank fart
Like a regular fart, except this type of fart is from having lots of anal sex, which has a looser and sloppier sound.
Bill slips a loose sounding fart. Mike says, "Damn Bill, by the sound of that skank fart, you must have dropped the soap a few times." or, Alexia cuts one after a set of porn and the directer says "Alexia! Get your skank fart(ing) ass out of here!"