Kourtney Kardashian and her boyfriend Younes Bendjima ''are very serious.''

The 'Keeping Up With the Kardashians' star has been dating the handsome model, whose identity was kept secret until recently, for just over a year now and it looks like things are hotting up between them relatively fast now as he has been staying round her home when her kids Mason, seven, Penelope, five, and Reign, two, are with their father Scott Disick and he's been invited to the family's famous festive party.

A source told E! News: ''They are very serious. He has been staying at her house a lot, but only if the kids are not there. They will be spending holidays together and Younes is invited to the Kardashians' holiday party.''

However, news that the former boxer is allowed to celebrate the festive season with them probably won't go down too well with Scott as he ''screamed at the top of his lungs'' when he found out his former flame had moved on with someone new.

Kourtney, 38, said previously: ''Last night I went to dinner with a guy and was photographed and I just felt like I should give Scott a heads up out of respect, even though he hasn't done the same to me in the past. But the photos never ended up coming out in the end so it was pretty much all for nothing.''

And her sister Khloe Kardashian, who had witnessed the phone call, added: ''He was screaming at the top of his lungs.''

The 34-year-old businessman - who dated Kourtney on and off from 2006 until last year - even threatened to beat up Younes at one point via a text to Kourtney.

In a recent episode of 'Keeping Up With The Kardashians', Kourtney read out a text message from Scott about her new boyfriend and said: ''He's like 'Your little friend is going to get beat up'.''