Sarah Larson Laps Up Ashlee Simpson's Sloppy Seconds

For an event held in Utah, the Sundance Film Festival sure featured a lot of sex and alcohol!

First, Paris Hilton was rumored to have made out with 43-year old MySpace CEO Chris DeWolfe.

Now, reports state that Sarah Larson - the Las Vegas cocktail waitress and ex-girlfriend of George Clooney - was “provocatively grinding half a dozen men on the dance floor — all at once” at the Hard Rock Hotel & Casino after-party for the film The Vicious Kind.

By the time the night was done, Larson had latched herself on to Ashlee Simpson's former flame, Ryan Cabrera... literally!

“Sarah was grinding on Ryan all night, her legs wrapped around his waist, massaging the small of his back,” said a source.