Scott Disick Has 'Come to Terms' with the Fact That Kourtney Kardashian Has Moved on: Source

Scott Disick is no longer “hung up” on his ex Kourtney Kardashian.

After officially calling it quits in 2015, both Disick and Kardashian have moved on from their nine-year relationship. Disick is dating 19-year-old Sofia Richie while Kardashian is with Younes Bendjima.

And a source tells PEOPLE that the parents of three are finally in a “good place.”

“Scott and Kourtney are on better terms,” the source says. “He was hung up on Kourtney forever and really wanted to make that relationship work, but he’s finally come to terms with the fact that she’s moved on.”

Disick and Kardashian share sons Mason, 8, Reign, 3, and daughter Penelope, 5.

Along with improving his relationship with his ex, the source says Disick has also slowed down his hard-partying ways.

“He’s not partying like he was just a year ago and seems to be in a healthier place mentally and physically,” the source adds. “Everyone in the family is really happy with how he’s doing lately.”

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Disick was most recently seen celebrating his 35th birthday with Richie in St. Barts with his kids. The couple has been officially dating since last September after initially sparking romance rumors a year ago.

“Scott and Sofia have a super solid relationship and seem really happy together,” the source says.

In recent months, the relationship appears to have gotten increasingly serious, with Richie spending plenty of time with Disick and Kardashian’s children.

A source previously told PEOPLE Kardashian “trusts” Richie with the kids.

“The kids are allowed to spend time with her,” the source said. “Sofia likes having them and helps Scott. So far, the kids are giving Kourtney good reports about Sofia.”