Uh oh, it sounds like Kyle Richard's invite to Paris Hilton's wedding might get lost in the mail! Sources exclusively told In Touch that the 37-year-old heiress kicked Kyle off the guest list as the feud between her and Paris' mom, Kathy Hilton, has yet to be resolved. "Kathy has resentment about Kyle's upcoming TV show, American Woman," the source said. "Which is inspired by the life of their mom."

Kathy is more than upset about the whole thing and Paris is obviously taking her side. But their troubled relationship isn't a secret. During the Real Housewives of Beverly Hills reunion, Kyle spoke about how they aren't on great terms at the moment. Kyle even admitted that she hasn't spoken to her older sister in more than six months, however, she hopes things will change once Kathy actually watches the show.

kathy hilton and kyle richards

"I'm looking forward to her seeing American Woman, because I think she's going to look and say, 'I read the situation wrong,'" the reality star explained during the reunion episode. "And then we’ll go from there."

She continued, "I told her all the time. I said, 'I'm not sharing your stories or Kim's — these are my own stories.' And not only that, it's a fictionalized version of our life, and our mom being a single mom in the '70s is the jumping-off point."

kathy hilton kyle richards

The show is set to premiere on June 7, so Kathy will have plenty of time to change her mind about the show and the way she feels about her sister's involvement with it. But, the source exclusively told In Touch that if Kathy doesn't have a change of heart, "Kyle is going to miss her niece's wedding." And while Kyle has been very vocal about the television show and her feud with Kathy, she's kept quiet on whether or not she'll be at Paris' November nuptials.

Paris got engaged to Chris Zylka in January 2018. The pair were on a romantic ski trip in Aspen when Chris got down on one knee and popped the question.