‘KUWTK’: Kourtney Kardashian Upsets Kim Kardashian Over Treating Nanny Poorly

Kim Kardashian had a heated argument with her sister Kourtney in Thursday's episode of “Keeping Up with the Kardashians” over “degrading” the family's nanny.

Kourtney, 42, told the nanny during a recent family trip that she would never allow her kids to be around her ever again. She was upset because the nanny had called her youngest son, Reign, 6, “a liar.”

However, Kim, 40, told the nanny that she can work for her after the woman cried worrying about her job.

"Kim's nanny and I had a little disagreement when we were away traveling together," Kourtney says during a confessional in the episode. Kim then confronts Kourtney about the incident and says that her nanny "felt so degraded by you, and you just started yelling at her and you said, 'Keep your voice down,'" which Kourtney said was a “lie.”

Kim rejects her sister's excuse, and sides with the nanny, saying: “It should have been in private.

Kim tells Kourtney: "She said [she] wish[ed] you would've tapped [her] on the shoulder and said, 'Hey, something's really bothering me. Can I talk to you?' and [you] could have talked in private. But for her to yell at me in a restaurant [was wrong].’”

Kourtney then counter argues that it was the nanny who raised her voice, and snaps: “She would never work for me the way she acts.”

Kourtney explains that she wanted to confront the nanny in front of Reign so that he knows "I have his back." Kim then hits back at her sister, saying: “I like her so she's not getting fired. I like to keep my staff for a long time, so that's how I feel.”

"If you think she works for you, that's totally fine. She would never work for me with the way she acts. That's totally your choice… She will not ever be around my kids," Kourtney replies.

Slamming her sister, Kim says: "Kourtney, you can't even keep a nanny."

After the fight, Khloé goes to check with her sister Kourtney and finds her crying. Kourtney then tells Khloé that Kim "uses s--t against you. It's just like, that's the stuff that makes me question like why would you treat your family like that? It's so f----- up."

Later in the episode, the sisters settled down the situation by having a calm conversation. "Keeping Up With the Kardashians" airs on E! every Thursday at 8 p.m. ET.