Lisa Vanderpump used to be the queen of the Real Housewives of Beverly Hills, but on Monday night's episode of the Bravo show, Brandi Glanville took Lisa down a notch, in convincing Kyle Richards that the restaurant owner wasn't really her friend.

Brandi told Kyle that Lisa had put tabloids containing articles about Kyle's husband Mauricio's alleged cheating into her suitcase, hoping she would take them on the gang's Palm Springs trip.

And on the explosive episode, Kyle and Mauricio appeared to believe Brandi, and confronted Lisa. The question for viewers: Was it all a jealous Brandi lie to drive a wedge between Lisa, her former BFF, and Kyle?

The trouble began when the RHOBH cast members went on vacation together in Puerto Rico to visit co-star Joyce Giraud's home country.

Brandi, simmering with anger about perceived slights from Lisa, confided to Yolanda Foster that she felt Kyle had replaced her as Lisa's close friend. (Unsurprisingly, Yolanda was taking bestie Brandi's side, telling Bravo's cameras that Lisa was a phony.)

Although Lisa used to call her every morning, Brandi said now she called Kyle.

"I feel like I'm on the down," Brandi fumed.

Brandi was also angry that Lisa seemed to take every opportunity to befriend Scheana Marie, Lisa's SUR waitress who had once had an affair with Brandi's then-husband, Eddie Cibrian, as she felt that Lisa had exploited her marital breakup pain on TV by constantly shoving Scheana in her face.

Brandi also took a harsh dig at Lisa, saying she had her one-time houseguest Cedric Martinez deported back to England before the show's season before was filmed after the two had a falling-out.

Even though she was admittedly intimidated and "scared of" the British beauty, Brandi was determined to confront