In a clip from Sunday's new episode of "Keeping Up with the Kardashians," Kendall vented some major frustrations to Khloe after their vacation left a bad taste in her mouth.
"We went to Mammoth. To be honest, it was kind of a lot for me," said Kendall. "A lot of the trip, people were picking on me -- and by people, I mean Kourtney most of the time. Whether or not she thought she was joking, I didn't really think it was a joke."
In a confessional, Jenner said that while she loves how close she and Kourtney have become, Kardashian was out of line on their trip.
"To be honest, I felt like there were just some moments where she was a bit rude and it really started to get to me at a certain point," she explained.
After hearing Kendall's complaints, Khloe said she was "so annoyed with Kourtney" as well in a confessional. "She is supposed to be the older sister, but it just seems like Kourtney was bullying Kendall the entire time."
A fight between Kendall and Kourtney has been teased for the upcoming episode of "Keeping Up with the Kardashians," which airs Sunday on E!