Gerard Butler Admits Brandi Glanville Hook-Up: 'Didn't Know She Was A Celebrity' (WATCH VIDEO)

Gerard Butler confirmed that he slept with Brandi Glanville on the The Howard Stern Show on Monday. The actor also slammed her for spilling the beans on their brief tryst.

Butler, 43, appeared as a guest on Stern's show and was asked if he slept with the Real Housewives of Beverly Hills star after she told Andy Cohen that the 300 star was the most famous man she ever slept with.

Butler admitted he had a fling with the reality star after they met at a beach party.

"We were at a beach party. We were having fun...We hung out. We had a little bit of fun," Butler confessed.

Butler, however, said that when they met and did the deed, he didn't know who she was or her last name. He also expressed disappointment with the fact that she spilled the beans about their brief affair.

"I didn't know her last name," Butler explained. "I didn't know she was a celebrity...I didn't know she was going to f**king tell people about it."

Butler told Stern that he called Glanville up to let her know that he didn't appreciate her revealing their tryst.

"I called her and I said, 'One, I'm not really happy that you did that because there are certain things you got to keep a little private," Butler said he told Glanville. "And two, I am sorry because I said I didn't know who you were."

Butler laughed and explained that Glanville cried during their chat, telling him: "I am doing a book tour and nobody is asking me about the book, they just are saying that Gerard Butler says he doesn't know who you are."

Glanville released a tell-all book, Drinking and Tweeting and other Brandi Blunders on Feb. 12. It revealed details of her marriage to her now ex-husband, actor Eddie Cibrian, and his cheating ways.

Glanville appeared on Bravo's Watch What Happens Live on Jan. 23. The show's host, Andy Cohen, asked her "Who is the most famous person, besides Eddie Cibrian, that you have hooked up with?"

"Uh, Gerard Butler," Glanville told Cohen.

Cohen then asked Glanville more questions about her most famous Hollywood hook-up.

"Was that more than once? Was it a relationship?" Cohen asked.

"No, no, no. It wasn't a one nighter, it was like a little week of fun," Glanville revealed,

Cohen asked her to rate Butler's bedroom skills on a scale from 1 to 10.

"Eleven," Glanville told Cohen.

TMZ asked Butler a few days later about his brief affair with Glanville and he replied, "Who's Brandi Glanville?"

Watch Gerard Butler discuss Brandi Glanville on Howard Stern's radio show in the short video below