KUWTK Reunion: Kourtney Kardashian Says Ex Scott Disick's 'Substance Abuse Was the Deal-Breaker'
The Keeping Up with the Kardashians reunion special, hosted by Andy Cohen, will air in two parts beginning on June 17
In the new sneak peek at the upcoming "Housewives-style" reunion, airing in two parts beginning June 17, Cohen covers everything from Kourtney Kardashian and Scott Disick's breakup, to Tristan Thompson's cheating scandals and Kris Jenner's relationship with ex Caitlyn Jenner.
"Welcome to a sit down 20 seasons in the making," the Watch What Happens Live host begins in the new clip. "For the first time ever, I'm grilling the Kardashian-Jenners."
"My mom's a bit nervous," Kim Kardashian tells Cohen behind the scenes.
"We're all feeling a little overwhelmed, we've done it for so long," Kris replies.
Kim, 40, then opens up about a mysterious moment between her and her mom.
"What people don't know is you said to me, 'I'm gonna put you in a car, no one will find you - just leave,'" she says as Kris, 65, adds, "And I'll take care of it."
Cohen then asks Kim about her apologizing to an unnamed man. "Do you think you owe him an apology?" he questions, to which Kim says, "Absolutely."
Conversation next turns to the relationship between Kourtney, 42, and Disick, 38, who split for good in 2015 after dating on and off for nearly a decade.
"Do you think your relationship might have turned out differently if you hadn't shared so much of it?" Cohen asks.
"Probably, but I think the substance abuse was the deal-breaker," says Kourtney, referencing her ex's past struggles with alcohol. (The star checked himself into rehab twice in 2015, and again sought treatment last year.)
"I was pretty irresponsible," Disick tells Cohen, who goes on to ask Disick about Kourtney's new relationship with Blink-182 drummer Travis Barker.
RELATED VIDEO: Andy Cohen Says 'Everything' Was Discussed at KUWTK Reunion - Including Kim Kardashian's Exes
"So do Kourtney and Travis have your blessing?" he says, though the clip doesn't show any response.
Next up is Khloé, 36, and her relationship with Thompson, 30, whom she got back together with last year following his multiple cheating scandals.
Never miss a story - sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
"When Tristan first cheated on you, how did you know it will be done again?" Cohen asks Khloé before the teaser concludes with one last question directed at matriarch Kris.
"Kris, have you forgiven Caitlyn for how she treated you?" Cohen asks Kris about her ex.
The Keeping Up with the Kardashians series finale airs Thursday at 8 p.m. ET on E!, with the first part of the reunion following at the same time on June 17.