A source tells PEOPLE that Kardashian, 37, wants her ex to make good choices for the sake of their three children: Mason, 7, Penelope 4, and Reign, 2.
“Kourtney is very disappointed for the kids,” the source tells PEOPLE. “It makes her upset when he parties for days.”
Just last week, Disick made a surprise appearance at the Kardashian and Jenner family’s Costa Rican vacation after he was initially “disinvited” by his ex after he partied at Sundance and was spotted with a “very Kendall Jenner-like” brunette.
But in the two days after Kardashian and Disick wrapped the family vacation, the father of three jetted to Miami, where he spent his time cuddling up poolside to models.
“It’s just totally unacceptable behavior for a 33-year-old with three kids,” the source says. “The kids keep asking for him and it’s just sad.”
Although the former couple, who ended their nine-year relationship in July 2015 after he was spotted cozying up to another woman, were making strides in improving their relationship — including living together again last fall — they appear to no longer be on the same page. While reconciliation appeared to be on the horizon for the Keeping Up with the Kardashians star and her ex, a source previously told PEOPLE that Disick “was working to get Kourtney back but has given up again.”
The source tells PEOPLE that since Disick returned from Miami, he is no longer living with Kardashian and the children but is instead living alone in his Hidden Hills home.
After the family vacation, another source told PEOPLE: “Kourtney hasn’t been happy with Scott for weeks. It has nothing to do with what he is doing in Miami right now. She just doesn’t like when he parties. He is an irresponsible dad when he parties.”