A source exclusively tells E! News the Keeping Up With the Kardashians alum is "beside himself" following the news that Kourtney is engaged to Blink-182 drummer Travis Barker, who popped the question at the Rosewood Miramar hotel on Sunday, Oct. 18.
According to a second source close to Scott, the Flip It Like Disick star "knew it was coming," as the Kardashian-Jenner family had "mentioned it to him before." Nonetheless, the warning did little to soften the blow, with the source sharing that Scott is "still really sad about it and is feeling low."
Scott and Kourtney's on-again, off-again relationship began in 2006. They dated for more than 10 years, during which they welcomed Mason, Penelope and Reign, but never married.
But Kourtney broke up with Scott for the final time over the Fourth of July weekend in 2015. At the time, a source explained the Poosh guru was upset with Scott's behavior, saying, "Kourtney has always taken Scott back and been by his side, but now with three kids it has gotten old."
Fast forward to present day and the second source says, "He will always care for Kourtney. She is the mother of his children and no one else will compare to that."
For now though, the first source says Scott "can't speak to Kourtney," with the second insider saying that Amelia Hamlin's ex is avoiding the newly-engaged couple.
"He will always be a part of the Kardashian family but it is hard for him to be around Kourtney and Travis," the second source explains.
Scott's apparent disapproval of Kourtney and Travis was made evident when he allegedly DM'd her ex-boyfriend Younes Bendjima in late August. Younes shared a photo of the message, in which Scott allegedly wrote, "Yo is this chick ok!???? Broooo like what is this. In the middle of Italy."
A separate source told E! News that Kourtney knew Scott had "issues accepting her love with Travis."
"She just wishes he would know better than to reach out to Younes of all people," the insider said.
"Scott Disick is still very bitter about Kourtney and Travis' relationship. He wants her to be happy, but behind closed doors, he will always have regrets about their relationship and why it didn't work out," another source close to Scott later told E! News. "He is bitter because he's never seen Kourtney this serious about someone."
Even so, the insider said that Scott "regrets" speaking to Younes about Kourtney.
Then, on Oct. 7, E! News reported the Flip It Like Disick star was moving on from the ordeal and shifting his focus from his relationships to his kids. The source said, "That's his priority right now."