RHOBH : Kathy Hilton Breaks Down in Tears Discussing Past Estrangement from Sister Kyle Richards

Kyle Richards and Kathy Hilton have overcome a lot to get to where their relationship is today.

During Wednesday's episode of The Real Housewives of Beverly Hills, Kyle and Kathy got into a deep conversation about their previous "setbacks." The chat kicked off with a recap of what happened at Lisa Rinna's Rinna Beauty launch party, where a lip reader provided readings for the entire cast.

For Kyle's reading, the interpreter said her kiss was "wide open" and that there was still "so much healing" to be done, adding, "And I'm telling your mom to get out of this conversation."

"What's my mom saying?" asked Kyle, 52.

"She's saying, 'Kyle, do not betray me,'" the lip reader replied.

After Kyle and Kathy, 64, sat down for lunch, the conversation turned to American Woman — a short-lived Paramount Network series co-executive produced by Kyle starring Alicia Silverstone as the pair's late mother, Kathleen Richards.

RELATED: The Real Sisters of Beverly Hills — See Kathy Hilton, Kim & Kyle Richards Before Housewives Fame

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"There's been so many things that have been out there, and there's just no way that they would have been interested in a script about Angelina Jolie [and] her mom. They're not writing one about Greta Garbo and her mother," Kathy said. "Do you know what I'm saying? It really put Mom in such a bad, bad light."

Kyle questioned Kathy about what put their mother in a "bad light," resulting in Kathy claiming it was "jealous people that made comments." Kyle argued that American Woman was "a love letter" to their mother, who died of breast cancer in 2002.

"It was inspired by [her story]. I mean, I said that until I was blue in the face," Kyle said, to which Kathy responded, "I mean, if it was such a love letter to Mom, why wouldn't you have talked to [our sister] Kim [Richards]?"

Kyle said she previously spoke to Kim, 56, about the series during a time when she wasn't "really speaking" to Kathy.

"I just wouldn't do that without talking to you," Kathy said.

"If it was a real story about Mom and us, I wouldn't have done it, but it wasn't," Kyle replied. "I liked the idea of something in the '70s and seeing a single mom and how they didn't know how to navigate, you know, without their husband."

Kathy maintained that "there were a couple of things that were just off-color" to her, citing a scene in which Silverstone, 44, was shown floating in a pool with a champagne bottle and money.

"You know, I didn't like that," Kathy said, adding that many people reached out to her with criticism of the series. To that, Kyle insisted "that's just people loving to create problems," adding, "We have a lot of outside, toxic people contributing to the issues between us."

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Kathy then brought up how Kim "never once said one unkind thing," leading the pair into a discussion about how the trio have been estranged from each other at different points over the years.

"When my mom passed away, the dynamic between Kathy, Kim and I changed, because my mom was always the mediator," Kyle said in a confessional. "If my mom was still alive, we would've still had the arguments that we had, 1,000 percent. But all the years of not spending time together, my mom would never have tolerated that and she would have brought us all together, always."

Noting that "time" allowed the pair to heal, Kyle added through tears: "Now, we can just be together and have fun, and I don't ever want to go back to that place."

Kathy then revealed her one "regret" during her 10-year estrangement period with Kyle. "[Not] being together," she said, beginning to cry.

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Kathy recently opened up to PEOPLE about how joining RHOBH this season has allowed the two sisters to become closer.

"I never would have thought I'd say yes to this," she said. "I stopped watching it after the first season. My sister Kyle and I had our ups and downs so it was nothing that I wanted to watch. But Kyle convinced me to do it. And I was flattered. I thought it would be an opportunity for us to spend time together. I really missed her."

"It feels so good to be where we are now," she added.

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