Kourtney Kardashian has slammed Scott Disick for "flaking" on their children.

Kourtney Kardashian

Kourtney Kardashian

The 'Keeping Up With The Kardashians' star has blasted her former partner - with whom she has sons Mason, five and Reign, 11 months and daughter Penelope, three - for missing their kid's first day of school.

With Kris Jenner as mediator whilst the two exes spoke on the phone, Kourtney explained: "There was [a policy], but that has changed. He was flaking too often, every time I've tried to have him sit and have dinner with them, he sits in the other room on his phone.

"He flaked on going to the kids' first day of school. He says, 'I can't go because I hate school s**t, 'cause I get anxious.' When really, he went out and, like, parties through the next day. Just like a real f***ing a**hole."

The 32-year-old model made no comments on the accusations.

Meanwhile, Scott previously admitted he was finding it "really hard" following the pair's split.

He said: "It's been a really hard time going from, like, having all of you guys to having nobody. I f***ed up. I made the worst decision I could've ever made in my life."