Scott Disick Reveals Kourtney Kardashian's Mean Nickname for Kim Kardashian in 'KUWTK' Preview

Kim Kardashian is trying to explain away why she called sister Kourtney Kardashian the "least interesting to look at" during their brutal fight earlier this season on Keeping Up With the Kardashians — but in the process, Kourtney's mean nickname for Kim is revealed, potentially making the situation even worse.

In a sneak peek for Sunday's KUWTK episode, Kardashian, Kourtney and Kourtney's ex-boyfriend, Scott Disick, sit together and discuss why exactly Kardashian called Kourtney the "least interesting to look at."

"Oh my God, people are going so crazy," Kourtney says. "People hate Kim for her comment on the show."

"They hate me," Kardashian agrees, before rehashing the situation to Disick. "What I meant is you're the most boring."

"People are like, 'I've been abused by my family for years and I know that that's very hurtful," Kourtney says.

"That's bad. I knew that they would do this to me. I knew it would happen," a resigned Kim says.

"Yeah, but that's like anything you say, you gotta be careful," Disick tells Kardashian.

"Let's not justify it!" Kourtney chimes in, which is when Disick reveals his longtime ex's hurtful name for her younger sister.

"But that's your sister! You say bad things about her too," he says. "You call her a porn star every time I talk to you."

Kourtney brushes off the comment: "Yeah, right," she says. Kardashian seems unbothered by the revelation, so it's possible that she either let it go for the sake of ending the argument, or that it's not the first time her sister has called her that.

KUWTK fans will remember the fight that began with Kourtney not wanting to squeeze in the family's annual Christmas card photo shoot between her busy appointments. It ended with an explosive argument that took over the show's storyline for a few weeks and had many people on social media defending Kourtney.

While the backlash is still airing on episodes of KUWTK, Kardashian apologized to her older sister via social media at the end of October. After sharing a photo of herself side by side with Kourtney, she wrote, "I lied. She really is the most interesting to look at..."

It wouldn't even be the last time on the season where Kardashian insults her sisters. During a trip to Tokyo, she called sisters Kourtney and Khloé Kardashian "clowns" for the way they were dressing and said that they were cramping her style.

"Like it's actually embarrassing," Kardashian said in a confessional at the time. "Kourtney with her Japanese inspired outfits and Khloe with her silver sequins and turquoise eye shadow, huge chandelier earrings. They're just completely clashing and making my outfit look really bad and they're ruining everything."

Later in the show, Kourtney defended herself and Khloé. "But I feel like, we're also here to like, have fun, wear some fun stuff, do some fun hair and makeup, whatever, and by the way, I liked all my outfits," she said.

"I don't know, I saw what I saw and I saw f—ing clowns," Kardashian replied.

That particular spat occurred in March, so the sisters have surely patched things up by now.

Keeping Up With the Kardsahians airs Sundays at 9 p.m. ET on the E! Network.