The upcoming episode was filmed in December, when Rob took to Snapchat to call out Chyna for leaving with their infant daughter, Dream.
After the blowout fight, Kim heads over to Rob’s house with her mother’s boyfriend, Corey Gamble.
"We're all worried about Rob, so I brought Corey with me to Rob's house just to see what was going on," she explains.
During the sit-down with Kim and Corey, Rob confesses to being "hurt" by Chyna and implies that the 28-year-old model may not be sincere about her feelings for him.
Though Kim tries to stay neutral, she can't help but question Chyna's motives.
"I've always been super cool with her," Kim says of Chyna. "I have a different relationship with her than what guys have -- and with Kylie -- and I always hear her out and stuff. But just seeing the motive is hurtful."
Kim gets even more candid in a confessional interview. "I've always felt like them as a couple is just not that healthy, and I think they know it too," she says. "It's not just like some secret."
Meanwhile, Rob isn't totally off the hook. Kim points out that her younger brother can be "really irrational"at times, and needs to learn to "take responsibility" for his actions instead of blaming Chyna.
"It's so clear what this relationship is, and that they're just not meant to be with each other," Kim admits.
In another sisterly chat, this time at Kris Jenner’s house, Kim attempts to help lift Rob's self-esteem: "What happened to where you're so insecure that you think she has the power? You have the power."