In the new trailer of 'Keeping Up With The Kardashians', Kourtney Kardashian breaks down in tears after discovering then-boyfriend Scott Disick cheated on her.

The 35-year-old mother of three called it quits with Disick in July, after photos of him getting too comfortable with ex-girlfriend Chloe Bartoli during a holiday in France broke the internet.

Kris Jenner was seen checking the photos online exclaiming, "what a piece of s-t!"

In the emotional scene, Kourtney wipes her tears during a conversation with sister, Kim, saying "I've worked so hard to keep this family together."

US Weekly reports that the mom of five-year-old Mason, three-year-old Penelope, and nine months old Reign won't take the kids' father back anymore.

"She really has had it this time," a source told the magazine. "She can't believe he'd be so stupid to embarrass her and be photographed all over Chloe."

"Scott misses his family, but it's not enough to motivate him to change," another source told Us. "He doesn't have the constitution to cure himself of his issues."

Their 59-year-old momager, however, told Access Hollywood that she's "always hopeful" for Scott and Kourtney to reconcile.

"Scott is like my son," she recently said. "He came over yesterday. He was on his way over to see the kids. He's a great dad. They've got things to figure out."

The new trailer also gave a sneak peak on Kim, Kanye and North's trip to Jerusalem, Kris' reaction to Caitlyn Jenner coming out, and what the rest of the girls, Khloe, Kendall and Kylie had to say about it.

"I still have a long way to go before I can process all of this," Kris tells Kim in the video. "He's gone."

Catch the full episode of Keeping Up With The Kardashians, Sundays at 8:30 PM ET on E!.