Entertainment TV Scott Disick Is 'Struggling' with Kourtney Kardashian and Travis Barker's Relationship: Source Kourtney Kardashian and Travis Barker made their relationship Instagram official after Valentine's Day By Dory Jackson Dory Jackson Instagram Twitter Website Dory Jackson is an Associate Editor for PEOPLE's digital TV team. While at the brand, she's had the opportunity to interview a long list of celebrities, from Kate Hudson to Pierce Brosnan to Billy Porter. She also recaps popular TV shows like The Real Housewives of Beverly Hills and Vanderpump Rules.The New York-based Maryland native graduated from Randolph-Macon College in May 2016 with a focus in Communication Studies and Journalism. She came to PEOPLE in March 2021 after working at a number of major news companies, including Newsweek and Us Weekly. She also previously co-hosted a podcast called "Idol Nation." People Editorial Guidelines Published on April 21, 2021 05:05 PM Share Tweet Pin Email Scott Disick has not had an easy time seeing ex Kourtney Kardashian move on with boyfriend Travis Barker. A source tells PEOPLE that while Disick, 37, "has struggled" and "has been jealous" of Kardashian's past romances, he recognizes a difference in her flourishing bond with Barker, 45, compared to her previous relationships. "With Travis, he is struggling even more. Before Travis, Kourtney's relationships were never serious. It was more like flings. With Travis, it's different," the insider says. "Scott was pretty shocked when he found out that they are dating, and he can tell that they have moved very quickly," the source continues. "His kids love Travis, which is also hard for Scott. Kourtney and Travis are like a family with the kids. Scott is having a hard time with this situation." Getty (3) Kourtney Kardashian and Travis Barker's Sweetest Photos Together The source notes that Disick "has many regrets" regarding his former relationship with Kardashian, 42. "He knows that he messed up their relationship and let her down. For a long time, he still hoped that they would end up back together," the insider adds. Listen below to the episode of our daily podcast PEOPLE Every Day for more on Scott Disick's reaction to Travis Barker and Kourtney Kardashian's romance. Kardashian and Disick split in 2015 after dating on and off for nine years. They have forged a close friendship as they continue to co-parent their three children: Mason, 11, Penelope, 8, and Reign, 6. On an upcoming episode of Keeping Up with the Kardashians, Disick will open up to Kardashian about how he has struggled seeing her around other men. "I feel like I just don't like seeing you with another guy," Disick says to Kardashian in a sneak peek at Thursday's episode. "It hurt [sic] me when you're with somebody else and waking up to, like, looking at pictures of you with this guy you were dating. It was just unhealthy and it just made me upset and sad, you know what I mean? And now, I wake up with no real problems. I'm, like, care-free in the sense I don't have that, which used to take up a lot of space in my mind all day." 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. The Talentless designer continues, "The big fear is if you start dating again, then it goes back to that and I have to feel, like, a different way again and it's just hard. It sucks. I guess now that you're single and I'm single and you haven't been with somebody in a bit, either we figure out creating our own lives together or separately." Kardashian/Instagram KUWTK: Scott Disick Tells Ex Kourtney Kardashian He's Ready to Marry Her 'Right Now' in Sneak Peek PEOPLE broke the news of Kardashian's relationship with Barker, who was previously married to Shanna Moakler, in January. The pair made their love Instagram official with a hand-holding photo posted after Valentine's Day. A source told PEOPLE that the Poosh founder is "ready for a relationship with a more mature guy." When it comes to the Blink-182 rocker, the source said that he's "a super smooth guy and women love him, but he's not a player" and that he's "really nice, chill and is an adult." Meanwhile, Disick began dating Amelia Gray Hamlin a few months after his August 2020 breakup with Sofia Richie. The Flip It Like Disick star has been "telling friends how much [Amelia] means to him and how into her he is" as the relationship is "getting serious," a source told PEOPLE.