"I don't understand how my own sister is like talking shit about me," Kendall says and Kourtney yells back in defense, "I didn't even know there was a problem."
The trailer then flashes to Khloe shaking her head in disbelief as Kendall exclaims, "She will go out of her way to make me look crazy!"
The feud seems to turn playful though (and physical) when Kendall jokingly whips a bag at Kourtney. She then lunges at her sister and jumps on top of her -- but none of it looks all that aggressive.
But the sisterly drama is just the tip of the iceberg in the trailer as we see Kylie Jenner's reaction to the wild cheating scandal involving Khloe's baby daddy Tristan Thompson and the beauty mogul's ex-BFF Jordyn Woods.
"I don't even know if I should tell you this," a voice says in the video with shots of Khloe and Kris crying flash across the screen. A second voice adds, "Her legs were like in between his legs."
Khloe then breaks down in tears and says, "I am broken by so many things."
Kris also confronts Kylie about her then-bff. "For you and Jordyn, it's like a divorce," she says and Kylie bluntly replies, "She f--ked up."
"Keeping Up with the Kardashians" airs Sunday nights at 9 p.m. ET on E!