Nothing says betrayal like refusing to join a Conga line or drinking a competing tequila brand.

Try as she might to keep her cool, Kathy Hilton could take it no more on this (and last) week's episode of The Real Housewives of Beverly Hills.

While plenty of Housewives meltdowns have occurred off-camera, unfortunately for Kathy, 63, Lisa Rinna was a witness to hers, and though she has yet to directly confront the famous socialite, Lisa vented her frustrations in a lengthy confessional that ran throughout the episode — and the details are quite shocking.

Perhaps it was the altitude and all that tequila, but the entire trip was a series of fights and meltdowns and this one, according to Lisa, topped the list.

The episode opened at Kyle Richards' Aspen home as the women packed for their trip back to Los Angeles. "I'm on a mission from God to get out of here," an exhausted Lisa, 59, said as she wheeled her suitcase and prepared to leave. Kyle, 53, told Lisa she'd cried throughout the trip.

"My head is definitely in a fog after what happened last night. It's way worse than a hangover. We were at the club and Kathy was having an absolute meltdown. I've never seen anything like this in my life," Lisa added in a confessional. "I am not saying a whole lot 'cause I'm still in shock from what I experienced. It's not something that I would've ever imagined coming from anyone in this group, let alone Kathy Hilton."

"My sister doesn't want to come out of her room and it feels so weird to think I'm leaving my sister behind in Aspen because she won't get on the plane," a frustrated Kyle said in a confessional. "I'm just thinking to myself if she's this upset, somehow this is going to be my fault."

Lisa, Kyle, and the rest of the group — including Dorit Kemsley, Diana Jenkins, Sheree Zampino, Garcelle Beauvais, Sutton Stracke, Crystal Kung Minkoff, Erika Girardi, and Mauricio Umansky — boarded the jet. The group then discussed Kathy's absence.

"Kathy's not on the plane with us today because she had a breakdown at the nightclub that we were all at… that we saw," Erika, 51, explained in a confessional.

"Kathy was a little off. She kept asking everybody to do the Conga line and I don't think anybody wanted to do it. The next thing I know, she's in my face saying that she wanted to go home and 'If you don't go home with me you're not my friend,'" Sutton added in a confessional, pointing her finger at the camera to reenact the awkward exchange.

Crystal, 39, added in her own confessional that she saw a commotion but it didn't seem to be much at the time. "I've known Kathy for a long time, more than some of the other girls in the group. Like how bad could the behavior have been?" she asked.

In her confessional, a wide-eyed Diana, 49, described what she witnessed the night before. "I just saw her completely raging screaming at the girls and mostly at Kyle."

Kyle confirmed Kathy's rage in her confessional. "Kathy was saying she was pissed off and that I had to leave the club right now. I was very confused because I didn't even know what happened so I said, 'No, I'm not doing that. We just got here, Kathy.'"

Lisa was the one who volunteered to take Kathy back to Kyle's — but as she recounter, things only escalated from there. "We get in the sprinter van and Kathy starts screaming about everything and she'd say things like, 'I'm gonna take down NBC, Bravo, I will take down the show single-handedly. I will f---ing ruin you all!' What in the holy f---ing hell?" Lisa said in her confessional.

Lisa added more about how it got even worse when she and Kathy finally got back to Kyle's house and it was just the two of them. "She takes her glasses off, she throws them on the ground, she's jumping up and down, breaking her glasses, she's pounding the walls and she's screaming she 'made' Kyle… Kathy's responsible for Kyle and she said, 'I will destroy Kyle and her family if it's the last thing I ever do,'" she recalled.

Back on the plane, Kyle told the group that when she and her sisters were growing up, they'd get into vicious fights — some of them with Kim Richards that included biting, digging, scratches and drawing blood.

As Lisa texted Erika a play-by-play the night before, Kyle then admitted that she saw some of the messages and didn't want to go home.

"Kyle is way more famous and way more successful than Kathy Hilton's ever been," Lisa claimed in her confessional. "And clearly, Kathy is still holding on to anger over The Agency (Mauricio's very successful real estate company), American Woman (Kyle's 2018 sitcom that ran for one season that Kyle claimed paid tribute to their mother and Kathy has said painted their mom in a bad light). I think that it's been very hard for Kathy to have it all and then to have her sister have more."

In the midst of all the drama, Crystal invited the group to her home to celebrate her 39th birthday with a Great Gatsby/roaring 20s-themed costume party. Everyone attended except Kyle, who was headed back to Georgia to continue filming Halloween Ends. Prior to leaving, she said she hadn't seen or spoken to Kathy since the fight in Aspen.

"I really, honestly believed that we would never go to a bad place ever again," Kyle said in her confessional against a flashback to a previous time when she and Kathy had made amends after an argument. "And I don't know how I can fix this."

"You know, I'm getting tired of being the whipping boy when I know that there are others who display not the best behavior, " Erika said to Dorit, 46. "We've all seen each other at our worst. We've all heard things that perhaps were not the best. If you think I'm gonna be the f---ing whipping boy for this entire group, you got another thing coming, honey."

She continued to express her irritation in a confessional, arguing that she's consistently been called out for her poor behavior but others don't seem to be. "Sometimes those that are really, you know, like doing the best, are hiding the most. Remember, be careful of those who have a lot to protect. I don't have anything to protect," she said.

Dorit then said in her own confessional, "I think in this town the rules are a little different for the hyper-elite. Kathy's been in this town her whole life. She is part of a family that has a lot of strength, a lot of wealth, and a lot of connections. You have to think twice if you really want to challenge them."

Beneath the smiles at Crystal's birthday party, tensions were building in Lisa over Kathy's behavior. Lisa explained in her confessional how she was struggling after what she'd been through, telling the cameras, "I am very, very in shock still and I am putting on a brave face because I feel PTSD."

She ended up leaving the party early because she was uncomfortable that Kathy showed up and acted as if nothing out of the ordinary had happened.

"It is excruciatingly difficult to sit and watch Kathy pretend like nothing happened and it's starting to build in me and I'm super uncomfortable," she explained. "And if these women knew exactly what Kathy said about them, they wouldn't be real happy about it, I'll tell ya that. It's so f---ed up on every level. I am really trying but I feel like I have seen the devil and her name is Kathy Hilton."

Lisa added how she's known Kathy for years and described her as a polished and loving mother, a socialite and a pillar of society. "To hear all these things coming out of her mouth, I can't believe you'd think it, feel it, or say it about your own family," she said.

RELATED VIDEO: Kyle Richards Explains Why She May Not Return to RHOBH: 'I Just Want to Live My Life in Peace'

After Lisa left, without saying goodbye to anyone other than Crystal, the other women provided their thoughts on the matter — and a few said they saw a side of Kathy they'd never seen before. Kathy, on the other hand, didn't believe Lisa left because of her and instead speculated Lisa's issues were over the loss of her mom.

"I don't feel that she left because of what I shared with her in Aspen. She was a sweetheart. She listened. And I, by no means, got any indication that she was upset," she said in a confessional, adding that she was sorry if she was the reason Lisa left the party early because "I don't want to upset anybody."

Erika then went to another room to call Lisa but she didn't answer the phone. Diana joined her and said, "The Kathy I know is very put-together. The Kathy I saw in Aspen was not put-together. Kathy was f---ing raging. I don't even know who that person was."

Diana added that all the women should be held to the same standard and if anyone is misbehaving they should be called out.

"This game turns on everybody," Erika added in her confessional, as she said it's Kathy's turn now.

The last comment then led to a clip of next week's episode. "I saw what I saw. I heard what I heard and I will never f---ing forget it," Lisa exclaimed as she told the women how they were each talked about.

Then, the clip cut to Kyle. "I feel like you hate me or something," she cried to Kathy. "How could you say those things?"

Finally, Lisa is seen confronting Kathy. "You've got to figure out why you have a black heart," she told her.

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The Real Housewives of Beverly Hills airs Wednesdays at 8 p.m. ET on Bravo.

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