Although they split rather amiably in 2013, Bruce and Kris Jenner’s friendship appears to be quickly souring.

People reports that Bruce is seeing Ronda Kamihira, Kris’ best friend.

A source told TMZ that Kris is “torn apart and angry” at Bruce’s betrayal.

What’s worse is that, according to People, the two families grew up together with Ronda’s kids hanging out with Bruce’s kids, Kylie and Kendall.

A source familiar with the situation told the magazine that Kris “is just shocked.”

That’s not all. According to HollywoodLife.com, Kris unknowingly shared her “bedroom secrets” with Ronda, “giving her the blueprint for having sex with her ex.” The source told the website that Kris told her what “Bruce loved in bed and certain things he didn’t.”

According to People, Bruce and Ronda were first spotted together in Los Angeles at an Elton John concert on October 4. TMZ adds that since news of the relationship broke, Kris hasn’t discussed it with her soon-to-be ex-husband.