Ashlee Simpson got incredibly catty toward Pete Wentz’s ex girlfriend at a party in Los Angeles on Monday night. One source is even claiming Ashlee had to be dragged out of the bar to avoid an assaulting poor Michelle Trachtenberg, who Pete dated before Simpson. Apparently kids and matrimony can’t quell the crazy cakes female jealousy that erupts after a few drinks.

more photos of Ashlee and Pete after the hop…

It was reported today (via PerezHilton.com) that Ashlee was seated next to Michelle at a party, got a little tipsy, and let the vemon spew.

“Ashlee got very very drunk,” an insider reveals. “She also kept making frequent bathroom trips. As the evening went on and Ashlee started to get sloppier, things got out of control. She was staring directly at Michelle and starting hurling insults at her,” a source tells us. “She was grinding up on Pete like a stripper. It was actually pretty disgusting! [and saying] I hope you know, the whole time you were dating Pete, I was fucking him!”

The source then goes on to say that Ashlee had to be escorted out of the party, and Pete looked “mortified.”