New York, June 4 (ANI): It seems Pete Wentz’s wife Ashlee Simpson is still insecure when it comes to her man’s former flames.

On Monday night at Los Angeles’ Wiltern Theatre, the mum-of-one went out-of-control and loudly trash-mouthed “Gossip Girl” actress Michelle Trachtenberg, according to PerezHilton.com.

Ashlee, apparently, had to be restrained at the event.

The whole furore started when Wentz and Simpson were seated near Trachtenberg, who dated Wentz before Simpson met the Fall Out Boy bassist, reports The New York Post.

According to PerezHilton: “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 [Trachtenberg] some baby pictures of [Ashlee's] little boy, Bronx.”

But then Simpson started drinking.

“Things got out of control,” an insider was quoted.

Following the booze session, Simpson began to give Wentz a lap dance while staring directly at Michelle.

“She was grinding up on Pete like a stripper. It was actually pretty disgusting,” a witness told the Web site.

The heated situation came to an end when Simpson screamed at a confused Trachtenberg, “I hope you know, the whole time you were dating Pete, I was [bleep]ing him!”

Trachtenberg’s spokesperson didn’t comment on the incident. But Simpson’s rep said, “It was just a misunderstanding. Ashlee has since apologized to Michelle and they remain on good terms.” (ANI)