Source: Kourtney Kardashian Thinks Sofia Richie 'Way Too Young' for Scott Disick

Kourtney Kardashian is not a fan of ex Scott Disick's relationship with his new girlfriend, the much-younger Sofia Richie, according to a source close to the Kardashians.

“The initial reaction from Kourtney when she found out that Scott was dating Sofia was not positive," the insider told PEOPLE. "Like most people, she thinks Sofia is way too young for him and doesn’t get it.”

The 34-year-old Disick has been dating Lionel Richie's 19-year-old daughter since May 2017. The couple went on romantic trips to Europe and Mexico, which they chronicled on social media. In November, a source told PEOPLE their relationship is "serious" and "nobody notices" the 15-year age difference. They also spent the holidays together, with Disick posting a controversial video of Richie dancing in his kitchen while only wearing a sweater and underwear.

Although Kardashian has some misgivings about the relationship, the source told PEOPLE she has realized Disick is “doing so much better” with Richie in his life.

”He has very much shaped up in the past few months,” the source told the magazine. “Kourtney is happy Scott is doing better. Things between Kourtney and Scott are civil.”

Kardashian and Disick have three children – Reign, 3; Mason, 8; and Penelope, 5 – who found out “early on” about their father's new relationship. At first, Kardashian did not want Richie to meet the children, but since Richie has been spending so much time at Disick's house, she gave in. Now, the kids see their dad every week.

“Kourtney didn’t think it would last and she never thought Sofia was going to meet her kids,” says the source. “But now, Sofia spends a lot of time at Scott’s, so Kourtney allowed her to meet the kids. She has met them a few times.”

Kardashian's mom, Kris Jenner, grilled Disick about his relationship with a younger woman during an episode of Keeping Up With The Kardashians. He mentioned the relationship, but did not go into detail.

“Whatever makes him happy — I don’t judge, I don’t care,” Kim Kardashian West said.

“I think it’s a good thing," Kim said in the new episode. "I just hope that he’s making good choices and having fun and that nothing is getting crazy. … I mean, it’s not like we can keep tabs on him forever. He’s got to live his life. Kourtney’s moved on, Scott’s eventually going to move on. If it ends up turning into something, great.”

Kardashian is also in a relationship with a younger man. The 38-year-old Keeping Up With The Kardashians star is dating 24-year-old Younes Bendjima.