Kris Jenner's 'Biggest Life Regret' Is Cheating on Robert Kardashian Sr. With Caitlyn: 'I Made a Huge Mistake'

Kris Jenner confessed her "life's biggest regret" was cheating on her late ex-husband, Robert Kardashian Sr.

During the Thursday, October 26, episode of The Kardashians, the 67-year-old opened up about her past infidelity during a candid conversation with her daughter Khloé Kardashian.

"What was your mindset when you cheated?" Khloé, 39, asked her mom during a chat about her ex-boyfriend and baby daddy Tristan Thompson's lengthy record of unfaithfulness.

"When you did that with my dad, and you had four kids and you had a family? Yes, I know you were really young…" the Good American co-founder continued.

Kris agreed she was "really young and dumb," noting her age and lack of knowledge was definitely "something that plays into it because you don’t really understand the consequences of your actions."

"But what was my dad not doing that made you want to look elsewhere?" Khloé questioned of Kris — who tied the knot with Robert Sr. in 1978 and welcomed Kourtney, 44, Kim, 43, Khloé and Robert Jr., 36, before their divorce was finalized in 1991.

That same year, Kris tied the knot with Caitlyn Jenner, 73, who was formerly named Bruce prior to her transition in 2015.

"I don’t know because he was such a great husband and such a great dad, and I think that I fell into a situation where I thought that the grass was greener somewhere else, and I made a huge mistake," the momager expressed. "That’s my life’s biggest regret."

"I’m not proud of the way I behaved during that time, but you know what? Everything happens for a reason," she noted.

"I really do live my life by thinking God has a plan, and without that whole thing happening, there never would’ve been Kendall and Kylie [Jenner]."

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Kris and Caitlyn welcomed the 818 founder, 27, in November 1995, four years after they said "I do." Kylie, 26, came along less than two years later in August 1997.

While the former spouses had to wait till Kris' divorce was settled to officially exchange vows, Caitlyn previously shared the duo first met on a blind date in 1990, admitting the interaction was the closest she's experienced to "love at first sight."

Though it seems Kris and Caitlyn's brewing romance was the final straw in her and Robert Sr.'s union, reports have suspected for years that the mom-of-six's alleged affair with Todd Waterman in 1989 also played a major factor in her marital demise.

Elsewhere in the episode, Kris explained why she finds it so important that Khloé thinks twice before cutting Tristan, 32, whom she shares her daughter, True, 5, and son, Tatum, 1, with, out of her life for good.