Why Does Khloé Kardashian Call Kris Jenner 'One of the World's Biggest Liars'?

Khloé and her momager get into an argument over brother Rob Kardashian

Photo: E! Entertainment

Khloé Kardashian is not happy with Kris Jenner on this week’s Keeping Up with the Kardashians.

In a sneak peek at Sunday’s episode, Khloé and her momager get into an argument over the fact that Jenner financially supported son Rob Kardashian‘s new house purchase. (As PEOPLE previously reported, Jenner helped her son Rob, 29, buy a $2.285 million home in their family neighborhood of Calabasas, California in February.)

“You are one of the world’s biggest –” starts Khloé, 31, before Jenner cuts her off: “Enablers?”

“Liars,” Khloé corrects. “You are a liar. You are lying.”

“I’m not a liar, he has the money for the down payment,” says Jenner, 60.

Khloé falls silent, exasperated, and turns to sister Kourtney Kardashian, 37, who was also at the table.

“Like, seriously, everyone?” she demands.

“What? What did I do now? Why are you so angry all the time?” Jenner says as Khloé lets out a sarcastic laugh.

“Do you have a cough?” Jenner asks.

“I’m just allergic to bulls—,” Khloé snaps back.

In an on-camera confessional, Khloé explains she’s particularly frustrated that her mother is now the one insisting on helping Rob, while Khloé was the one who tried so hard to help him during his two-year hiatus from the public eye living in depressed reclusion.

“I would have such deep fights in my family because I was ‘enabling Rob’ by letting him live with me, then the one person who yelled at me the most – which is my mom – now she’s helping Rob?” she says. “I just find it mind-blowing.”

“He’s very excited, and I want you to be supportive and get on board,” Jenner continues in the clip.

“I don’t even talk to Rob!” Khloé responds.

“I know, but just if you happen to see him,” says Jenner.

Rob, 29, emerged from his reclusive lifestyle earlier this year after going public with his relationship with Blac Chyna, to whom he’s now engaged to and with whom he announced last Friday he’s expecting a child.

RELATED VIDEO: Rob Kardashian and Blac Chyna Make First Appearance Since Announcing Baby News

The relationship created major tension among Rob’s family as Chyna, 28, has a rocky history with the Kardashian-Jenner women.

At the time, sources told PEOPLE Khloé in particular felt "betrayed," but most recently, sources have said Khloé and the rest of the women in her family are doing their best to accept Chyna and bury the hatchet.

“Khloé loves and supports Rob and always has. She’s always been his biggest supporter and has been trying to get him on the right track for years,” a source recently told PEOPLE. “So, naturally, it was a little harder for her to accept the fact that all of a sudden Blac Chyna was the one who got him into the land of the living again.”

And while the source said “Rob and Khloé had some tough times, like he did with the rest of the family, … the bottom line is he’s her little brother.”

“She’ll never turn her back on him,” said the insider.

Keeping Up with the Kardashians airs Sundays (9 p.m. ET) on E!