Justin Bieber & Kourtney Kardashian Hot Hook-Up Scorches Selena Gomez & Scott Disick: Ellen DeGeneres’ LOL

Justin Bieber and Kourtney Kardashian are enjoying flirty fun canoodling. But for his ex, Selena Gomez, and her baby daddy, Scott Disick, it’s not so much fun. Kourtney hasn’t tried to hide the hot hook-up with the singer, and even though the 36-year-old reality star may seem like an unusual choice for a 21-year-old pop star, Kardashian has gotten to the point of allowing Justin to baby-sit one of the the three children (Mason Disick) that she and Scott share, reported Celeb Dirty Laundry.

Disick has, therefore, issued an ultimatum, notifying Bieber to stay away from his children. Just one problem with his issues about the romance that Kourtney is enjoying: Kardashian originally tossed Scott out the door because he had an affair with someone much younger. Is it a reverse mirror case of deja vu dating?

However, seemingly ignoring the fact that he did it himself, Disick views it as humiliating to see Kourtney behaving in a way that he considers childish. And he’s laying down the law as far as Bieber spending any time alone with any of the children that they share, or making any attempt to take on a fatherly role with Reign, Penelope, and Mason.

Scott has his own problems, however. He recently completed rehab, and Kris Jenner is so concerned about the potential for a relapse that she’s decided to drug-test him to continue shooting Keeping Up With The Kardashians.

But regardless, Disick is in denial about any wrongdoing on his part, and is focused on ensuring that Kourtney keeps the Biebs far away from the children. And if Justin doesn’t, Scott has warned Kardashian that he’ll do something. No word on precisely what form that revenge will take.

With Disick behaving that way with regard to Kourtney and the pop star, how is Selena handling the romance? She’s found herself in somewhat of a love triangle with Niall Horan, according to the Irish Examiner.

Although Bieber is dating Kardashian, he’s also keeping his eyes on the blossoming romance between Gomez and Niall. Horan is finding himself bombarded with questions from the pop idol about what’s happening. Could the One Direction star find himself in water hotter than the hook-up between Kourtney and the Biebs, who followed up with texting Niall?

Selena advised Horan to avoid getting involved in any type of love triangle trap, and Niall followed through. They’ve been boosting their PDA profile since she flew to London to show her support for his big performance with the rest of the One Direction stars on The X Factor.

With all that drama, can Kardashian and Justin hope to have peace and love for the New Year? Not if Disick has his way, according to Hollywood Life.

Scott has reached out to Kourtney to let her know his belief that Bieber is exploiting her and wants to woo her back. And Disick is playing the kid card just as if it were a game to see who can win Kardashian.

“Scott actually wants to try and work things out with Kourtney. He thinks Justin is just using her and will eventually hurt her in the long run,” a source told Hollywood Life.

Disick doesn’t want his children to discover that Kardashian is involved with her boy toy, and had been dreaming of a happy family reunion for the holidays.

But it’s Ellen DeGeneres who’s having the last laugh on the topic of Kourtney and the Biebs. Taking to Facebook, Ellen shared a photo-shopped picture and her wit about the hot hook-up between Kardashian and her pop star passion.

“We’re just friends, everyone,” joked DeGeneres for the caption.

[Photo by Dimitrios Kambouris/Getty Images for Dom Perignon]