The tears were flowing during Kendall Jenner's trip to the Greek island of Mykonos earlier this spring. While vacationing with her famous family -- including a then-pregnant Kim Kardashian -- the 17-year-old model often felt excluded from group activities. To avoid feeling left out, she decided to spend some time alone in her room. In a sneak peek from the Aug. 4 episode of Keeping Up With the Kardashians, half-sister Khloe Kardashian-Odom pays Jenner a visit to see what's going on.

"Kendall is not at breakfast. Last night she said she felt left behind, and I would never want Kendall to think we didn't want to hang out with her," Kardashian-Odom, 29, says in a video confessional. "If Kendall wanted to hang out with us, the door's open! We're your sisters."

When the former X Factor co-host enters her sister's room, Jenner shouts, "No! Leave, Khloe! Leave! Go away!" Kardashian-Odom persists, telling her sibling, "I want to talk to you."

Bursting into tears and breathing heavily, Kendall gets out of her seat and heads for the back door. "I'm not filming this," she sobs. "Go away, everybody."

To find out why Jenner is so upset, watch the clip above and tune in for an all-new episode of E!'s Keeping Up With the Kardashians on Sunday, Aug. 4, at 9 p.m. EST.