Ashlee Simpson reportedly had a strange run-in with her husband Pete Wentz’s ex-girlfriend Michelle Trachtenberg.

According to reports, the two women met at Jay-Z and Eminem’s performance at the Wiltern Theatre in Los Angeles on Monday night.

An onlooker reported: “The evening started off very civilly.

“Pete and Ashlee had a pleasant conversation with Michelle and her boyfriend for close to 20 minutes, and even showed [Michelle] some baby pictures of their little boy, Bronx.”

But as the evening wore on and the drinks began to flow: “Things got out of control. [Ashlee] was grinding up on Pete like a stripper. It was actually pretty disgusting.”

When she was done, she is said to have shouted at Michelle: “I hope you know, the whole time you were dating Pete, I was f***ing him!”

Ashlee’s spokesperson explained: “It was just a misunderstanding. Ashlee has since apologized to Michelle and they remain on good terms.”