asimpson020411party.jpg Ashlee Simpson-Wentz confirmed that she was divorcing Pete Wentz on February 9, but it looks like she was already celebrating her new life as a single gal, as she was spotted partying hard with several girlfriends at Trousdale and later at Eden nightclub on February 4.

"She was drinking Grey Goose and Sugar-Free Red Bull all night," a witness tells Us Weekly. Ashlee arrived at 1am, and she wasn't skimping on the cocktails either. "She was laughing a ton. She didn't care who was around her...she was just there to have fun," the source added.

Though it was reported yesterday that the reason for their split was Pete's demanding tour schedule, it seems as though Ashlee's penchant for partying was an issue as well.
A source tells the mag that late nights and "being out of control" were putting a huge strain on their three year marriage. Hmm, I guess there is another side to the story after all! But who are you siding with -- Ash or Pete?

Click the gallery below to see more shots of Ashlee's night out on the town!