Was Lisa Vanderpump demoted from her full-time role on "The Real Housewives of Beverly Hills" to that of a "friend" amid filming on the Bravo TV reality show's ninth season? Following rumors of a cast feud between Vanderpump and her co-stars, a fan of the series spoke out on Twitter and offered a theory about what is going on behind the scenes.

“Theory — [Lisa Vanderpump] didn’t refuse to shoot [VIDEO] the promo shot with the other women," the fan wrote.

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"What if [Bravo TV] decided to make her a friend of the ['Real Housewives] this season, and that’s why she wasn’t shooting with them?! Neither [Bravo TV] nor [Lisa Vanderpump] wanted to reveal this to the other women, so they made it seem like she refused to shoot," the Twitter user continued.

"[Lisa]’s been noticeably absent at group events,” the fan added. And a short time later, she received a response from Lisa Rinna herself, who immediately shot down the idea of Vanderpump's role being reduced from full-time to part-time. “Bulls**t,” she said of the rumor.

Lisa Vanderpump was caught in a lie?!

According to a report from Us Weekly magazine, earlier this month, the "Real Housewives of Beverly Hills" cast isn't currently speaking to Lisa Vanderpump after supposedly catching the reality star and restaurateur in a lie. That said, no one knows what Vanderpump allegedly lied about and from the looks of things, the ladies have been unable to find a resolution for their situation.

“The women feel like [Lisa Vanderpump] doesn’t want to face them and confront the situation," an insider explained to the magazine.

"She has kept her distance and now that’s creating more problems with the cast," the source added. In recent photos of the cast filming, Vanderpump has been nowhere in sight. Most recently, a number of women, including Denise Richards, Teddi Mellencamp, and Kyle Richards, attended the bridal shower of Camille Grammer, but Vanderpump wasn't seen in photos of the incident.

Lisa Vanderpump has another show in Bravo

As she began filming the ninth season of "The Real Housewives of Beverly Hills" in Los Angeles over the summer, Vanderpump was also busy filming the upcoming seventh season of her reality series, "Vanderpump Rules," which is based out of her West Hollywood restaurant, SUR Lounge.

For more of Lisa Rinna, Lisa Vanderpump, and their co-stars don't miss the ninth season [VIDEO] of "The Real Housewives of Beverly Hills" when the show returns to Bravo TV later this year.