Kris Jenner Admits She Cheated on High School Boyfriend With Robert Kardashian

Kris Jenner is revealing a scandalous detail about her past with Robert Kardashian in Sunday’s episode of Keeping Up with the Kardashians.

In a sneak peek of the show’s newest episode, Kim Kardashian and Khloé Kardashian sit down to watch a tribute video Scott Disick made for Jenner.

“I’m really excited for my kids to see my legacy video,” says Jenner in a confessional. “Because they’ll have that forever — and who knows, maybe they learned a thing or two about their mom that they didn’t know before.”

The video shows Kourtney Kardashian‘s ex interviewing Jenner, who reveals that her relationship with their late father, who was her first husband, started when she was dating someone else.

“Back in the spring of 1973, I was 17 years old,” she says. “I actually had a boyfriend who was always out of town. His name was Cesar. So while he was living on the road, I met Robert Kardashian.”

Khloé, shocked by the news, begins to tease her mom, calling her a “hussy” and joking, “Oh my God, you’re such a whore! Now we know where we get it from.”

But Jenner’s story isn’t over yet. She revealed that one day when Robert was over, Cesar returned home unexpectedly.

“Well, it wasn’t pretty,” she admits. “Not proud of it. Actually, Cesar tried to grab his sweater. I think he ripped a hole in Robert’s sweater! I didn’t want to ever hurt anybody’s feelings.”

Jenner also talks about a health scare from her past, revealing that she once had a bone tumor that would have caused her left leg to be amputated if it had been determined to be cancerous.

“You did?” Khloé shouts while watching the video. “I did not know that.”

“I cannot believe Scott made this legacy video,” Kim says.

“I think it’s so sweet,” says Khloé. “So much I think we think we know about mom — but we really don’t.”

Disick appears to be redeeming himself after a tough beginning to the season, in which he was struggling to control himself while dealing with moving on from Kourtney.

In one worrying episode of the show, Disick called the mother of his children while allegedly drinking, threatening to beat up her new boyfriend, Younes Bendjima, if he attended the Cannes Film Festival with the reality TV celeb.

Later, when confronted about his outburst, he admitted his behavior was inappropriate. “There’s a lot of anger, like it’s really real, us not being together,” he said, adding, “I let it get way too out of hand.”

But in more recent episodes, he’s been staying sober and sane, even refraining from drinking while hanging out with Jenner during New York Fashion Week.

Keeping Up with the Kardashians airs Sundays at 9 p.m. ET on E!