Kim Kardashian Reveals the Most 'Frustrating' Thing Kris Jenner Does as a Grandma

Kim Kardashian is getting candid about Kris Jenner's role as a grandma.

While appearing as a guest on iHeartRadio's What in the Winkler?! podcast, the SKIMS co-founder, 44, opens up to host Zoe Winkler about what Jenner, 69, is like as a grandma to her four kids — daughters North, 11, and Chicago, 6, and sons Saint, 8, and Psalm, 5 — and reveals the most "frustrating" thing her mom does when it comes to looking out for her grandchildren.

"This is the one really frustrating thing that my mom does," Kardashian begins. "My mom is like the most judgmental when it comes to snacks and candy. Then her house has every candy, ice cream — it's like a kid's heaven."

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The momager recently celebrated her 69th birthday on Nov. 5, and Kardashian recalls an example of her mom's judgment from the celebration.

"So she invites us over and then my son went into a freezer last night to get — it's her birthday, so she has cake — and he goes, 'I don't want cake, I want an ice cream instead,' " the reality star recalls.

Jenner then watched as Kardashian's son ate the frozen treat and said, "Look at him eating the ice cream." Kardashian adds, "I'm like, 'You have it and you're judging me?'"

"My mom judges me like I'm the worst because I allowed them to have an ice cream that they had at her house," Kardashian says.

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Kardashian shares all four of her children with ex Kanye West.

In October, a source close to the mom of four told PEOPLE that Kardashian's life revolves around her and West's four kids. The source also noted that Kardashian is "pretty much a single mom," as West, 47, is often "not around."

"Kanye is sadly not around very much. She's pretty much a single mom," the insider told PEOPLE. "Although she has help, it's still a lot of work for her to balance and coordinate everything."

The source continued, "Kim's life is around her kids' schedules. When they are in school, she works. When they are off, she's very much focused on being a mom." They add that the SKIMS co-founder "is not even dating anyone now. It's all about work and the kids."