We can't believe Rob Kardashian talks to Kris Jenner with that mouth!

In a video posted to Kourtney Kardashian's Snapchat, the 29-year-old can be heard going off on his 60-year-old mother.

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“There’s something so wrong with my brother, I just want you guys to know that,” Kourt says laughing as Rob tells Kris, "Hey, Mom, why don’t you shove your d–k in my mouth?”

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A post shared by Kourtney Kardashian Snapchat (@kourtneysnapchat) on

While the comment appears to be in jest, we don't know many boys who could get away with speaking to a parent like that!

The only son of the business mogul did show a softer side last week after Kris was injured in a car accident, sending her gold balloons that spelled out the words, "Love You Mom."

“I love you too Rob!!!! Thank you for the beautiful balloons and for loving me the way you do!!" Kris responded on Instagram.

Scroll through the gallery below for a look back at the famous family's best insults!