Though Disick landed in Los Angeles on Friday, a source tells ET that his ex, Kourtney Kardashian has been "worried" about him "falling off the deep end."
"This is something that Scott has struggled with for years, and something Kourtney has dealt with since she has known Scott," the source explains. "When Scott starts partying, he can't stop. There is no middle ground for Scott -- it's go all in or none at all. This is how he has always been."
"Kourtney has had enough and does not want him around the kids until he can figure his own problems out," the source reveals, adding that the Keeping Up With the Kardashians star hopes Disick "gets the help he needs." "She has been through this before, but knows he's a good father and never wanted to punish the kids with not seeing their father because of Scott's actions. The kids are getting older, especially Mason, where they know that something is wrong."