Mary McCormack wants out of her 10-year marriage to former Smash director Michael Morris after he was caught kissing married singer Katharine McPhee.

"He wants to keep the family together, but as far as Mary is concerned, it's over," an insider told Life & Style. "There's no going back...Mary only found out this week about the affair after he confessed everything to her. She had no idea anything had been going on. The last thing she ever thought was that he was seeing another woman."

The couple has three daughters together. McCormack has already kicked her husband out of their home, according to Us Weekly. 

One source said, "[Mary] is so cool and the nicest person. It's so sad that this happened to her. She's truly great."

Morris' marriage might be ending over the racy pictures showing him cheating, but McPhee and her husband split up more than six months ago, according to a new report.

One source close to McPhee said, [Katharine] has had friends living with her for months," while a different insider added, "She is SO embarrassed she was caught. She should have known better!"

McPhee and Morris were spotted kissing Sunday, Oct. 22, in the parking lot of I Panini Di Ambra in Hollywood. The end of her own marriage could explain why she was not wearing her wedding ring at the time.

McPhee and Morris have not commented on the scandal.