Vanderpump Doesn't Rule Anymore! 'RHOBH' Queen Breaks Down After Brandi Glanville Exposes Her To Kyle Richards

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 Lisa about the situation on the trip.

On a beach outing in Puerto Rico, Yolanda decided to have a pow wow with Lisa, telling her Brandi felt there was a divide in the group.

"I haven't done anything wrong," Lisa said.

"Are you a Hollywood friend or a real friend?" Yolanda pressed.

Brandi then joined in and told Lisa, "You're moving away from me and back towards Kyle."

Lisa walked away and Brandi told the cameras that "she can't handle a conversation."

"They're mean. I want to go," Lisa cried to husband Ken Todd.

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It wasn't the first time she'd had doubts, as Kyle admitted to the cameras, "Lisa has not always been supportive of me."

Meanwhile, things got heated between Lisa's husband Ken and Yolanda as he told her it was Brandi's issue, not hers!

When Kyle asked Lisa if she'd tried to stir up trouble by making Brandi pack the offending tabloids, Lisa denied it.

But Kyle didn't know who to believe.

"I'm so confused," she told the cameras.

Kyle's sister Kim Richards then told Mauricio the story of what Lisa had allegedly done, and the husband who has weathered infidelity rumors exploded, "That's a f***ing b**** if you ask me!"

Mauricio, who has always denied cheating on Kyle, went over and confronted Lisa and her husband.

Both denied it with Ken vehemently telling him, "It's a lie!"

"She's the perfect woman. Maybe that's what they don't like," Ken told the cameras about his wife.

Still, Mauricio was skeptical.

"I don't know what to believe," he told Lisa and Ken.

Later, over dinner with everyone present at their Puerto Rican resort, Kyle said she wanted to know the truth about the tabloid story.

Both Brandi and Lisa claimed the other was lying.

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The situation led to the rest of the cast taking sides, with Kim telling Ken, "You're a big, stubborn old man. Shut up!"

Lisa and Ken then fled the dinner in disgust.

"We're out of here!" Ken said.

After they left the table, Mauricio told the others, "I want to know who my friends are, for sure."

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Back in their room, Lisa and Ken shared a drink and cigarette together as they vented their frustration about the trip gone awry.

"I won't defend anyone in the future," Lisa said. "Especially not Brandi, who's creating that s***."