The Real Housewives of Beverly Hills drama continues even off-screen as Denise Richards is reportedly upset over Brandi Glanville's claims that she has an open marriage.

Recently, Brandi spilled that the two of them had been hooking up for months last year.

"Denise was stunned to hear that Brandi was saying they hooked up and she has an open marriage," a source told HollywoodLife.

 "Brandi has been telling everyone that Denise and Aaron have an open marriage, and Denise is adamant that a hookup never happened. All of this has actually sparked the end of Denise and Brandi's friendship," the source added.

Denise denies Brandi's claims, but Brandi is not letting it go.

"Brandi is trying to paint Denise to be a liar and that's something she's not. Some of the RHOBH cast has been listening to Brandi, but a lot of them don't know who to believe," the source continued. "It's shaping up to be a huge storyline for the upcoming season, as it's caused major fighting between the women and a lot of name calling amongst the cast has occurred."