After 10 years in the publicity-savvy Kardashian family, Kourtney’s ex Scott Disick has learned how to grab a headline. So when Rob Kardashian’s former fiancée, Blac Chyna — who’s suing Rob, his sister Kim and their mother, Kris Jenner — threw a first birthday party for daughter Dream at her LA home in mid-November, Scott made sure to show up for the mermaid-themed bash. Says a Kardashian insider, “He knew it would create some buzz and piss of Kourtney and the family.”

It did — and his next move could start a war. Scott, 34, is threatening to write a tell-all about the entire Kardashian clan, multiple sources tell In Touch. And one insider says a juicy, detail-packed tome could command up to $10 million. “Scott knows all their secrets, the skeletons in their closets and where all the bodies are buried,” says the insider. Though he’s moved on from Kourtney with 19-year-old model Sofia Richie, the insider says Scott wants revenge on the family for capitalizing on his addiction issues and personal demons for ratings on Keeping Up With the Kardashians for years. Adds another source: “He won’t hold back. Everyone is petrified about what Scott could reveal.”

Kourtney is particularly panicked. Though Scott often appeared as the villain on the E! show, the 38-year-old mom of their three children, Mason, 7, Penelope, 5, and Reign, 2, “was no angel herself,” says the source. During the exes’ nearly decade-long on/of romance, Kourtney had her fair share of flings, including a whirlwind romance with Justin Bieber in 2015. “Scott will reveal details about her relationship with Justin,” says the source. “He plans to name all of her boy toys.”

Expect a few titillating passages on Kim, 37, and her husband, Kanye West, too. “Kourtney told
Scott about Kim and Kanye’s volatile marriage,” says the source, adding that he also knows all about Kim’s outrageous diva demands and “how she and Kanye lead separate lives.”

“Scott knows a lot of personal details about the Kardashians,” says a Kourtney friend. “Everything from their plastic surgery secrets to how much Kris really drinks.” A Kourtney friend adds that Scott has shocking new details to spill about Kanye, 40, who was hospitalized after a breakdown in 2016: “Scott knows [the truth] about Kanye’s mental health.”

kourtney kardashian scott disick kids instagram

Family matriarch Kris, 62, may soon regret ever opening up to Scott. “Kris has shared a lot of the family history with Scott, including her wild life and secret affairs,” says the source. “A lot of it happened back when she was friends with O.J. Simpson and Nicole Brown Simpson.”

Encouraging Scott to go for the jugular: Chyna, 29. She’s suing Rob, Kim, and Kris for defamation and interference with contractual relations over her canceled E! show, “and she’s telling Scott all the juicy details about Rob being a ‘controlling, jealous nightmare,’” says the source. Of course, Scott knows plenty of dirt firsthand — the two used to be close friends who would spend lots of time together. “Back when he and Rob were friends, Rob would moan to Scott” about his mom and sisters, says the source. The Kourtney friend says Scott considers Rob’s depression and pot smoking fair game, too.

Bracing for the worst, the Kardashians have begun to do damage control. Kourtney and her family members “told all the nannies and [friends] not to say much when Scott is around,” says the Kourtney friend. They’ve also considered asking him to sign a nondisclosure agreement barring him from speaking about the family, but “things could get even more ugly if they broach that subject,” says the source. Besides, he has no reason to. Explains the source, “Scott finally has the upper hand.”

For more on this story, pick up the latest issue of In Touch — and for more exclusive content sign up for our newsletter!

Have a tip? Send it to us! Email In Touch at