After having rough sex, the dude pops his red balls (resembling elmo) into the chick's ass, thus making it dirty. Afterwards, the chick can either lick it off, like a lollipop, or just enjoy the ball to anus pleasure. The definition is quite flexible.
Example 1 (balls into anus):
Dude1: Dude, she's so hot.
Dude2: I'm gonna enjoy poppin the dirty elmo.
Example 2 (lollipop licking the dirty elmo):
Dude1: Dude, I hear she's quite rough in bed.
Dude2: I hope she enjoys poppin the dirty elmo.
Ruler of Lake Titicaca. Rumored to have a bunghole that gets very angry if it does not receive toilet paper. Cornholio the Great is often seen walking around with his shirt over his head and his hands in the air, chanting songs about his power, and his bunghole.
"I am Cornholio! You do not want to face the wrath of my bunghole, for I need TP!"
Butthead: Shut up, Beavis! (uh huh huh huh)
Beavis: Um, okay. (heh heh heh heh).
Boys who enjoy yaoi (a genre in Japan that contains sexual and/or romantic relations between two men); literally translates to "rotten boy"; corresponding female : fujoshi