Kourtney Kardashian dumped Scott Disick because his partying ''embarrasses'' her.

The 'Keeping Up With the Kardashians' beauty has reportedly called time on her nine-year relationship with the 32-year-old star - with who she has sons Mason, five, and Reign, six months, and daughter Penelope, two - and insiders claim she grew tired of his wild lifestyle and heavy drinking.

A source told People magazine: ''He acts out, he rebels, he drinks too much and he embarrasses her.

''He acts like a kid sometimes. He just rebels against the crazy responsibility of having three kids and makes Kourtney do it all.''

And it has been claimed that Scott - who checked into rehab earlier this year - has a ''serious'' drinking problem and is still struggling to cope with the death of his parents, who passed away within a few months of each other in October 2013 and January 2014.

The source added: ''Scott has a serious drinking problem. He doesn't know when to stop, and he takes it too far.

''His parents' deaths really hurt him. He took it incredibly hard and was in a very dark place after it happened. It's still painful.''

It was previously claimed the final straw for Kourtney, 36, was seeing pictures of Scott getting close to his ex-girlfriend Chloe Bartoli in Monte Carlo.

A source said: ''Kourtney dumped him after she saw the pictures and he hasn't been home after a month-long party binge.

''Kourtney has always taken Scott back and been by his side, but now with three kids it has gotten old. Kourtney has to do what's best for the kids.''