Oh, brother! In a new Keeping Up With the Kardashians clip, Kim Kardashian worries about her brother, Rob Kardashian, after he mysteriously deletes all of his Instagram photos with his pregnant fiancée, Blac Chyna.

“What’s going on with my brother?” Kim asks Scott Disick in the clip from the Sunday, October 30, episode. “He just deleted all his pictures of Chyna and everywhere in the media it says they’re broken up.”

The Selfish author, 36, then decides to take matters into her own hands and give Chyna a call to see what’s going on and whether Rob will be attending grandma Mary Jo Campbell’s upcoming birthday party in San Diego.

The 28-year-old model explains that she and her fiancé, 29, had a fight, and he’s using it as an excuse to skip the birthday bash. “He does stuff for a reaction. For example, he asked me about his business stuff and then I gave him my honest opinion and he got upset with me,” Chyna said. “Honestly, I think he doesn’t want to go to MJ’s birthday party on Tuesday. And I feel like that’s what this is all about because [he thought], ‘If I start arguing with Chyna and I really don’t want to go, this would be even more reason for me not to go to MJ’s party and I can blame it on Chyna, maybe.’”

Kim later seems a little skeptical of Chyna’s account. “I know that Rob and Chyna have an unstable relationship,” she said. “There’s obviously two sides to every story."

As Us Weekly reported back in July, the couple were indeed going through a rough patch when the Arthur George sock designer wiped his Instagram account of any trace of Chyna. “They didn’t break up; they had a fight,” a source told Us at the time. “It was from the pressure of filming the show and everything moving too fast. Rob is just not used to filming again, and it’s been hard on him. Everything with Chyna is moving so fast. … She’s a single parent and filming the show and all of her other work commitments, so Rob has been feeling neglected by her.”

See what happens with Rob when Keeping Up With the Kardashians airs on E! Sunday at 9 p.m. ET. 

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