Kourtney Kardashian, 38, takes her job as a mother super seriously. And as of right now, she’s deemed her ex and baby daddy,Scott Disick, 34, not worthy of seeing their three shared kids:Mason, 7;Penelope, 4; andReign, 2. For Kourt, Scott’s taken his recent partying too far, and she doesn’t trust his seemingly reckless behavior! “Kourtney’s not furious about Scott’s partying, she’s more worried and upset, mainly because of the kids,” a Kourtney insider revealed toHollywoodLife.comEXCLUSIVELY. “Kourtney wishes Scott would just grow up and stop being so selfish — he’s a father of three, not some carefree bachelor with no commitments.”Scott has recently been photographedmaking outwith bikini-clad women in Vegas, and before that he was partying in Cannes with nearly a new woman every day —including actressBella Thorne, 19. Needless to say, Kourtney was not super pleased with what she saw, but she can’t say it surprised her. “Scott has always done exactly what he wants, and always put himself first, so Kourtney’s not particularly shocked by hisrecent behavior,” our source continued. “But she’sadamant that she’s not going to allow Scott around the kids while he’s acting like this — and it’s been a while now since he saw them or spoketo them.” Yikes!But as much as Kourtney fears for Scott, and doesn’t want him around their kids in his current state, she’s apparently deeply saddened to be “banning” him from seeing his children. “It breaksKourtney’s heart, because she really wants the kids to have their father in their lives, but she’s not taking any risks,” our insider explained. “It’s like Scott is a lost soul right now.” Even worse, Kourtneyfears her ex has started drinking again, even after his multiple trips to rehab!“Kourtney was really concerned about Scott’s behavior in Cannes, and she doesn’t want him around the kids right now as she doesn’t trust that he’s sober,” a Kourtney insider revealed to usEXCLUSIVELY late last month. “Kourtney doesn’t believe Scott was behaving like that sober, and she doesn’t want to risk her kids’ safety if indeed he is using again.” Looks like mama bear Kourt is DEAD serious! Better get your act together if you want to spend time with your little ones, Scott!