Justin Bieber & Kourtney Kardashian Flirt Amid Baby Rumor: Kendall & Kylie Jenner & Scott Disick Outraged

Justin Bieber and Kourtney Kardashian are heating up their hook-up, and Kendall Jenner is among those shocked by new rumors that Kourtney is now pregnant.

Kourtney Kardashian and Justin Bieber have enjoyed crooning and canoodling for months, regardless of those cougar comments from outsiders. But not everyone in their circle (or outside of it) is having such a great time watching Kourtney heat up her hook-up with the pop idol. Among those with jaw-dropping responses, especially since rumors are swirling that Kardashian is pregnant with the pop star’s baby, are her sisters Kendall Jenner and Kylie Jenner as well as Kardashian’s baby daddy Scott Disick.

But how did it all begin with the 36-year-old mom of three and star of Keeping Up with the Kardashians? Kourtney started her fling with the then-21-year-old pop idol just after splitting from Scott. Frustrated with his cheating, drinking, and partying despite repeated warnings, Kardashian ended her relationship with Disick last summer. And it was soon after that when rumors began that Kourtney was enjoying a fling with the Biebs, according to sources cited by Wonderwall.

The hook-up began in October and got hotter from there.

“Justin bragged to friends recently that he has been hooking up with Kourtney Kardashian,” said one insider.

Justin Bieber heats up his hook-up with Kourtney Kardashian.

Another insider noted the flirty fun was evident.

“Oh, yeah, that’s definitely happening and has been for some time now…Every time Kourtney and Justin are together they’re extremely flirtatious. They text each other all the time.”

More evidence and confirmation came late last year of the hook-up between Kardashian and Justin, reported People.

During one sighting of the couple, they were canoodling non-stop at a hot spot in West Hollywood called The Nice Guy.

“He and Kourtney were nearly inseparable – smoking on the patio together and were super touchy feely,” a source told People.

Questions arose when Hailey Baldwin seemed to be nudging Kardashian out of the way, but at his 22nd birthday party, Bieber made it clear that he was still affectionate with Kourtney by inviting her to the wild bash, reported the Daily Mail.

Kardashian had a blast, flaunting her fabulous figure in clingy black attire and taking her little sister Kylie Jenner as her guest for the evening.

But now has that hook-up turned into a baby bump for Kourtney? Hollywood Life cites a source claiming that Kardashian is pregnant, with Justin as the father, leaving Scott Disick distraught.

Prepare for an outraged response from Disick if that baby rumor turns into reality, warned the insider.

“Scott would be pissed, crushed and fly off the rails…That would really knock Scott out like a Mike Tyson punch.”

Moreover, Disick sees nothing wrong with continuing to party with other women himself while remaining possessive of Kourtney, added the source.

“Scott has a double standard, he likes to have his cake and eat it too. Problem is, he doesn’t want anyone taking a slice out of Kourtney. That’s his baby’s mother and the only thing he wants coming out of her womb are children with his DNA.”

As for how Kardashian’s sisters Kendall Jenner and Kylie Jenner feel with the rumors swirling that Kourtney is pregnant with the Biebs’ baby? Both Kendall and Kylie have been linked to Bieber in the past, and those past relationships with the hot pop star now hooked up with their older sister is turning what might have been surprise into angry shock over the reports that Kardashian has a blossoming baby bump, according to a source cited by Hollywood Life.

Kendall Jenner jealous of Kourtney Kardashian over Justin Bieber?

“They won’t be happy about a Bieber baby at all,” predicted the source. “They already think Kourtney is addicted to having babies. They’ll just call her weird and desperate. But Kourtney is ready for their criticism.”

However, Gossip Cop reports that Kardashian doesn’t need to get ready for criticism, because the pregnancy rumor is false.

The rumors began when the print copy of Life & Style proclaimed Kourtney’s Biebs baby in blaring headlines.

“Kourtney’s Pals Say She’s… PREGNANT BY BIEBER!…Justin can’t wait to be a dad…Kourtney Shocker: Pals Claim She’s… PREGNANT WITH BIEBER’S BABY.”

However, although Gossip Cop confirmed that Kardashian and the Biebs hooked up, the pregnancy report is denied by insiders.

“B.S.,” proclaimed a Biebs source.

[Photo by Xaume Olleros/Getty Images for Calvin Klein]