Kris Jenner has opened up about her past infidelity, admitting that her “life’s biggest regret” is cheating on the late Robert Kardashian Sr. with Caitlyn Jenner.

On Thursday’s episode of “The Kardashians,” Khloé Kardashian quizzed her mom on why she was unfaithful to her late father during a conversation about her ex Tristan Thompson’s own infidelity.

“What was your mindset when you cheated?” Khloé, 39, asked Kris, 67. “When you did that with my dad, and you had four kids and you had a family? Yes, I know you were really young…”

Answering the awkward question, Kris explained that she was “really young and dumb” and it’s “something that plays into it because you don’t really understand the consequences of your actions.”

Kris was married to attorney Robert Sr. from 1978 until 1991.

During their ill-fated union, the pair welcomed daughters Kourtney, Kim, Khloé, and son Robert Jr.

Kris Jenner has opened up about her past infidelity, admitting that her “life’s biggest regret” is cheating on the late Robert Kardashian Sr. with Caitlyn Jenner.HULU

Kris was married to attorney Robert Sr. from 1978 until 1991.Zimmerman

“The momager” met Caitlyn, who publicly came out as transgender in 2015, in 1990.

The pair ultimately got divorced in 2014.

“But what was my dad not doing that made you want to look elsewhere?” Khloé probed again.

“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,” Kris said. “That’s my life’s biggest regret.”

Kris met Caitlyn Jenner in 1990, and the pair ultimately got divorced in 2014 after Caitlyn came out as transgender.Ron Galella Collection via Getty Images

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

“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].”

Speaking about it further in a confessional later on, Kris explained why she hopes Khloé thinks twice before severing ties with the NBA player, with whom she shares daughter True, 5, and son Tatum, 1.

During their marriage, Kris and Rob Sr. welcomed daughters Kourtney, Kim, and Khloé, and son Robert Jr.Zimmerman

“When I got divorced, Robert and I became best friends. We talked on the phone all day long, helped each other through things all the time, and I did have regrets,” Kris explained.

“I thought, Wow, what I was thinking? So I want Khloé to be really careful when she makes these decisions and she has to let somebody go.”

New episodes of “The Kardashians” air on Thursdays on Hulu.