In a sneak peek at Sunday’s midseason finale, Kim and Khloé Kardashian sit down with momager Kris Jenner to discuss some tension apparently brewing between their brother Rob and his fiancée Blac Chyna.
“So, I’m trying to find Rob,” says Khloé, 32. “I’ve called him, I’ve texted him. He’s not responding.”
Kris, 60, tells her daughter that Rob responded to one of his friends that day and informed him he was at his house.
“So he’s not at Chyna’s house?” asks Khloé. “They’re still not talking to each other? How long is that going to go on for?”
“I don’t know,” Jenner says. “But I talked to Chyna and it scared me because it was everything that we had experienced with him, she was experiencing the same thing. So she wrote me last night and she said: ‘Can I see you tomorrow? I just really need to talk to you. Rob won’t talk to me.’ ”
When Khloé asks why, Jenner admits she doesn’t know.
“I haven’t gotten into the whole song and dance,” she says.
“Is he ever going to see his kid though, or is she going to take it?” asks Kim, 35, referencing the fact that Rob, 29, is expecting his first child with Chyna, 28, later this year.
“You really think they’re over?” says Khloé, sounding skeptical. “He seems like when I talk to him, he was very much in love with her. Am I missing something? How long have they not been speaking for?”
In an on-camera interview, Khloé expresses her concerns that her brother, who previously remained out of the public eye for almost two years while battling depression and weight gain, might be falling back into his reclusive habits.
“I know when my brother hurts how badly he does hurt,” says Khloé. “The more they’re fighting and the longer things are bothering him, the more depressed he gets. He’ll go into hiding again, go missing – I don’t want Rob to live that anymore.”
RELATED VIDEO: Blac Chyna Source Says She and Rob Are Still Together: ‘They’re Not Broken Up’
Though the timing of when the scene was filmed isn’t specified, the women could potentially be referring to a brief rough patch the couple went through earlier this month after Rob unexpectedly deleted all traces of the relationship from his Instagram account.
At the time, a source confirmed to PEOPLE that the couple had not broken up, though the pressures of filming their upcoming reality series Rob & Chyna appeared to be putting a strain on the relationship.
“Rob just got super emotional and felt too overwhelmed,” the source said of the brief tiff. “He lashed out from being frustrated, and they broke things off while they were filming. They got back together hours later.”
“Getting back in front of the cameras has been hard on Rob as he hasn’t been doing anything for a really long time now,” added the insider. “Being in the limelight all of a sudden again is a big deal for him. He’s working on himself and getting re-adjusted and taking things one step at a time, but things are definitely on the upswing for them.”
The Keeping Up with the Kardashians midseason finale airs Sunday at 9 p.m. ET, and Rob & Chyna premieres Sept. 11 at 9 p.m. ET, both on E!