"Everything is getting finalized," as per the custody agreement, a source said, but "there is nothing in writing yet."
"However, Kourtney won't allow Scott split custody," the source adds. "She thinks he is a drunk mess and not fit to be a parent without supervision."
In fact, she is so serious about this that she will "only agree to supervised and limits visits" between Disick and their children, the source adds. The two are also working out a "financial deal."
Scott's troubled history with alcohol abuse is well known, as he's been to rehab several times. It's also been chronicled on the multiple Kardashian family reality shows many times.
Kourtney and Scott split this summer after he was photographed getting a little too close for comfort with an ex girlfriend in Monte Carlo. Throughout their nine-year relationship, the former couple broke up and got back together several times. Many assumed that, based on history, they would find their way to each other again this time. That, however, doesn't seem to be the case.
"Kourtney really seems finished with Scott this time," the source said. She still "keeps an eye on Scott via social media," but she has "come a long way and instead of getting upset about Scott's latest shenanigans. It helps her realize splitting was for the best."
And while Scott is reportedly hanging out with 18-year-old model Lindsay Vrckovnik, Kourtney is simply focusing on her children.
"Although being a single mom is not easy, Kourtney is used to taking care of the kids by herself," the source says. "She has them on a great schedule and everything runs smoothly even when she is alone with them. She had some nanny help, too, since she is working, but she spends as much time as possible with the kids."
The three kids, the source says, "are her world, and she loves being a mom."
It's being presumed by many that Scott may be trying to work his way back into his ex's heart. Last week, he posted a photo of Kourtney on social media, calling her "1 hot mama." On Oct. 12, he again took to Instagram, perhaps getting a message to Kourtney, with the words "Never Give Up" written on a chalk board.