Despite the two sisters being on the show together, they had a massive falling out years ago, resulting in them not speaking for a long time and actively avoiding one another. Why did the pair fall out of touch?
Why did Kyle Richards and Kathy Hilton have a falling out? It started between their spouses.
The decade-long feud between the two sisters mainly has to do with some hard feelings between their spouses. In 2010, Kathy's husband, Rick Hilton, refused to make Kyle's husband, Mauricio Umansky, a partner at his real estate firm (the one that manages the Hilton hotels).
"Rick and his team wouldn't make Mauricio a partner, even after years of working there and a lot of success. So he left," a source told E! News in 2015.
Mauricio founded the Agency Real Estate, which has also found great success and become a rival for the Hilton conglomerate. The real estate company has been featured frequently on Bravo's Million Dollar Listing in recent years as a testament to its success.
"Rick did everything for Mauricio to get him started, he gave him clients, he introduced him to people. And then when Mauricio set up his own company, he did it covertly and informed Rick via email," the insider continued. "Mauricio was not made a partner as he was not being 100 percent above board and so there were trust issues. Finally, once Mauricio's new company was set up, Rick and Mauricio came to a gentleman's agreement that they would not go after each others' agents, but then Mauricio went back on that promise and tried to poach staff. It's a huge mess."
As the feud between their spouses continued, Kyle was also developing a TV show focusing on her life growing up with sisters — which quickly drew ire from Kathy, resulting in legal notices being sent between the sisters.
“I had my lawyer send her a letter saying absolutely do not include anything to do with me or my family in this show,” Kathy said on the show. According to the E! News insider, this notice was sent without any warning.
"Kathy did not want to come off negatively," the source said. "So that's why, for a period of time, Kyle was not going to [Kathy's daughter] Nicky's wedding. She was disinvited at the end of June, just weeks before the wedding. Nicky and Kyle are close, but Nicky deferred to her mom."
Kyle was eventually re-invited to the wedding, but the two remained distant for many years.
Are the two sisters speaking now?
The pair's feud continued for years, but only recently did they finally sit down to talk out their problems, and it seems the two sisters are finally on speaking terms again.
In an episode of RHOBH that aired in August, the two sat down to discuss American Woman, the show that Kyle co-executive produced for the Paramount Network. Kathy admitted that she felt the show put their mother in a bad light, while Kyle maintained it was meant to be a "love letter" to their mother.
"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."
Luckily, it seems the feud is finally over. See the two sisters talk it out on RHOBH on Bravo on Wednesdays at 8 p.m. EST.