Lamar Odom and Khloe Kardashian are in touch regularly and frequently, and this has Kim Kardashian West up in arms. She even went so far as to say it makes her sick during a recent clip previewing Sunday’s episode of Keeping Up With the Kardashians.

The clip shows Khloe getting a phone call from Lamar Odom.

“I’m with Kim, can I call you back?” Khloe asks. She and Lamar wind up chatting for a few minutes anyway, much to Kim’s dismay.

Khloe takes the call outside and Kim Kardashian West continues in an on-camera interview.

Kim Kardashian West confronts Khloé Kardashian about 'flirting' with ex Lamar Odom https://t.co/4tKkNcWjQw pic.twitter.com/buH33dmaml

— People magazine (@people) October 1, 2015

“I don’t know why Khloé and Lamar are talking, but he hurt her so badly,” Kim says of her sister and former brother-in-law.

“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,” she adds.

Khloe can sense that Kim is watching her, so she wraps up her call with Lamar Odom.

“Kim is staring at me, I have to go,” she tells him.

“Like, I just can’t take it,” Kardashian West says once Khloe has hung up. “The fact that when he decides to come around and be friendly, you’re like, flirting with him.”

“I’m flirting with him how?” Khloe asks. “By answering the phone and saying hello?”

“You’re just like, way more attentive,” Kim Kardashian West replies, adding that Khloe would be much more dismissive if the phone call had come from her other ex, rapper French Montana, rather that from Lamar Odom.

“Why would French and Lamar even be in the same category?” Khloe Kardashian asks.

This isn’t the first time Kim has expressed concern Khloe and her feeling of responsibility for Lamar Odom. She questioned Khloe when she checked up on Lamar while they were on their trip to Armenia. Khloe also was very supportive of Lamar this summer when two of his closest friends–Jamie Sangouthai and Bobby Heyward–died of drug-related causes.

Lamar Odom had a long stretch of drug problems himself, and rumors say he cheated on Khloe Kardashian.

Look who's back on Instagram after months away… http://t.co/qDSohQ5NiE pic.twitter.com/Hnw0UQMw6N

— Us Weekly (@usweekly) September 25, 2015

While Kim Kardashian West certainly has some right as a sister to express concern for Khloe, it’s ultimately up to her how much time she spends with or talking with Lamar Odom.

Do you think Khloe Kardashian and Lamar Odom will get back together? Khloe is reportedly dating James Harden, but not much about the two has hit the media in recent weeks.