Sean Penn and Charlize Theron's relationship may be over, but that isn't stopping the actor from trying to rekindle with his ex.

A source told Radar Online that the 54-year-old "Milk" actor drunk dialed Theron after attending U2's special show at the Roxy Nightclub in Los Angeles May 28. The source claimed Penn was acting like a single man during the party, but later drunk dialed Theron asking if he could come over.

"During the after party, Sean was very much acting like a single man on the prowl," the source told Radar, before adding, "Sean had been partying with the band, and he decided to call Charlize very late—it was obvious he was feeling no pain. He wanted to go over to Charlize's house, but she said no way... she refused to be a booty call!"

There have been no reports explaining why the couple unexpectedly ended their relationship. However, according to Us Weekly, Theron stopped answering Penn's phones calls and cut the actor off cold turkey. He reportedly moved out of her house several weeks ago.

Penn and Theron were, reportedly, inseparable at the Cannes Film Festival.

A source told Radar Online that the pair went their separate ways after filming "The Last Face" because working together on the project took "a toll on the relationship."

"Everyone knows how intense Sean is, and there is no exception on movie sets," an insider told the website. "Charlize felt he was overly critical of her at times. Separating work and personal became hard, and the lines were definitely blurred."