Britney Spears In 'Jackass: 3D': Star Does Porta Potty Bungee

03/30/2011 08:27 am ET | Updated May 30, 2011

Don't call Britney Spears a diva.

Spears, who is out promoting her new album, "Femme Fatale," appeared on "Jimmy Kimmel Live" on Tuesday night. So did "Jackass" star Johnny Knoxville. The two have history -- dirty history.

Knoxville revealed that Spears filled a scene for their latest movie, "Jackass 3D," and it was quite the crappy affair. Literally. Spears took part in the "Poo Cocktail Supreme," a huge bungee chord flight inside a used porta potty. You can guess what happened.

The scene was cut from the film due to time, but Knoxville had the footage to show Tuesday night. It's not pretty. But pretty hilarious.

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