Kim Kardashian Says She Feels 'Sick to Her Stomach' When Khloe Talks to Ex Lamar Odom

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Morning sickness isn't the only thing that's been making Kim Kardashian's stomach turn. According to the reality star she feels sick every time her sister Khloe talks to her ex Lamar Odom.

In this scene from Sunday's episode of Keeping Up With the Kardashians, Khloe and Kim are hanging out when Khloe gets a call from Lamar. Kim does her best to be cordial when Lamar says hi, but it's clear she's seething on the inside.

WATCH: Khloe Kardashian Reaches Out to Sisters Amid Lamar Odom Drama

"I don't know why Khloe and Lamar are talking, but he hurt her so badly," Kim explains. "As a big sister I'm just really protective, and for her just to be flirting with him on the phone makes me, like, sick to my stomach."

However, when Kim calls her sister out, Khloe isn't in the mood to get attacked.

"I'm flirting with him how?" Khloe asks, clearly annoyed. "By answering the phone and saying hello?"

NEWS: Khloe Kardashian: My Split from Lamar Odom Was a Catalyst for My Weight Loss

Lamar and Khloe tied the knot in 2009 after dating for several weeks. They stayed together until 2013 when they officially separated. Their divorce was finalized earlier this year, but the two have consistently stayed in contact since splitting.

This continuing relationship has been a source of tension between Kim and Khloe for some time, and may come to a head in this upcoming episode, which airs Sunday, Oct. 4 at 8 p.m. on E!.

WATCH: Kim Kardashian Completely Throws Khloe Under the Bus in a Game of 'Never Have I Ever'

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