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1.
Where drunk concertgoers break into cars in the parking lot and defecate on the driver’s seat.
If you’ve ever been to a No Talent Ass Clowns concert, you’ve probably seen or heard about “ass clowning” where drunk concertgoers break into cars in the parking lot and defecate on the driver’s seat. It is rumored to have started in 1996 at Consumption Auditorium when Nick Ray Tummo first committed the act. “I was drunk and my friends all thought it was funny so I figured why not keeping doing it at shows? It gives me a kind of special spiritual connection to the concert.”
by Lars Gunblade June 14, 2011
 
2.
a sexual fetish in whitch the couple paints one of there rear ends like a clown and begins to have relations with the clowns mouth
Mary: hey honey, do you wanna have sex?
Frank: sure, but can we do some assclowning
by bobbynom13 December 12, 2012