Justin Bieber & Kourtney Kardashian Heat Up Hookup? Mystery Reunion, Plus Scott Disick 'KUWTK' Bombshell [Video]

Kourtney Kardashian is reunited, and it feels so good. But does that apply to the 36-year-old reality TV star's romance with 21-year-old Justin Bieber, or with Scott Disick, the daddy of her three children? Or both? Out of all the Keeping Up With The Kardashians, Kourtney has become the most successful in the role of mystery woman, and that's especially true when it comes to her surprise hook-up with the playboy pop star.

Kardashian and the Biebs began their fling in October of last year, reported MTV News. Their hook-ups steamed up only a few months after Kourtney broke up with Scott. When Kardashian recently visited Ellen DeGeneres, the talk show host sought to persuade Kourtney to open up about the Biebs.

"We're friends. Yes," admitted Kardashian with a blush and a beam.

"You're smiling as if maybe it's beyond friends," probed Ellen.

"I've been smiling this whole time since I've been sitting here," responded Kourtney, quickly gulping down some water.

In addition, Kardashian and Justin devoted an entire evening together on January 27 at Los Angeles hot spot The Nice Guy, reported Hollywood Life.

Dressed to impress in her sexy finest, Kourtney flaunted her fabulous figure in sheer lace, while Bieber tried to hide out in a hoodie (sorry, but the paparazzi saw you anyway!). The two made separate exits, but rumors still ran rampant that the occasion was a mysterious reunion. Is it the first in a planned series of more oh-so-steamy hook-ups?

Biebs Brags About Hooking Up With Kourtney

While Kardashian issued her own statement on it to Ellen (well, sort of), the Biebs was shockingly candid in a recent interview of his own on the subject of his fling with Kourtney, reported Cosmopolitan.

The 21-year-old proclaimed that Kardashian is using him for a rebound romance and sex after her split from Disick.

"I'm being used, man. What can I say?" dished Bieber. "She's great."

And it's not just in interviews that the Biebs has been boasting about his fling with Kourtney. He's also been telling pals all about his hot new romance with Kardashian, two separate sources told Us Weekly.

"Justin bragged to friends recently that he has been hooking up with Kourtney Kardashian," said one source.

Kourtney attended Bieber's American Music Awards afterparty, and the two have been enjoying flirty fun for awhile, said the second source.

How Flirty Fun Turned Into Hot Fling

"Oh, yeah, that's definitely happening and has been for some time now," noted that second insider. "Every time Kourtney and Justin are together they're extremely flirtatious. They text each other all the time."

The odd couple have been spotted at a karaoke lounge Blind Dragon, and were described as "flirty... touching and laughing together" on another date.

In addition, Kardashian was seen at Bieber's favorite Beverly Hills hotel the Montage, where she didn't check out until 4 a.m. When they were together previously dining at the Nice Guy and enjoying Universal Studios' "Halloween Horror Nights," the 21-year-old made a positive impression, said one of Us' sources.

"When he was there with Kourtney, he was such a gentleman and so nice and respectful," noted the source. "He was definitely trying to impress Kourtney and act more mature."

Corey Gamble, his friend and ex-tour manager, is now the boyfriend of Kardashian momager Kris Jenner, keeping it all in the family.

But where does this leave Scott Disick? As seems inevitable in the world of Keeping Up With The Kardashians, it's complicated.

Scott Disick is still family to Kourtney Kardashian.
Scott Disick is still family to Kourtney Kardashian. [Photo by Chris Weeks/Getty Images for Calvin Klein]Kardashian and Disick were together for nine years before they broke up after he was seen cheating on her with an ex, reported MSN.

Scott subsequently went to rehab, and has focused on staying sober despite visiting Las Vegas on several occasions. And while Kourtney has been hooking up with the Biebs, Disick also has been associated with various new gal pals.

Kardashian recently posted a throw-back photo of the two together.

" #FBF with the baby daddy before he was a baby daddy," she wrote.

As for whether Kourtney and Scott are together? Kardashian explained on her recent visit to Ellen's talk show that while she views Disick as family, they are not reunited.

Kourtney Kardashian is still single and ready to mingle.
Kourtney Kardashian is still single and ready to mingle. [Photo by Michael Stewart/Getty Images for Kardashian Kollection]"We're not together," emphasized Kourtney. "I feel like every day is different, but we're totally getting along. Like, we have three beautiful kids together. He's family. He'll always be."

Disick Drops Bombshell

And when Scott visited Kourtney's sister Khloe Kardashian on her own talk show, Kocktails With Khloe, Disick dropped a bombshell about what he sees as the vast difference between how the viewers of Keeping Up With The Kardashians perceive him and his own reality.
"A lot of people think I only care about money and cars and don't realize it's more just about insecurities and how much I care about my friends and my family. I'd really rather never be in a tabloid again, but if I'm going to be, at least it be about, 'This guy isn't who everyone thinks he is.' "
And instead of cars and cash, Scott contends that his focus is on family.
"People say, 'Focus on work. focus on work. Make more money.' I have money. The more money I have, the less happy I am," revealed Disick. "The only thing I'm trying to focus on is calming down and focusing on the kids and trying to be a good dad."

In addition, on Khloe's talk show, Scott revealed a shocker about his dreams for his relationship with Kourtney, reported Hollywood Life.

Khloe demanded that he play "f***, marry, kill," giving Disick Kim, Kourtney and Khloe as his options.

"Bang Khloe, kill Kim and marry my girl," declared Scott.

KUWTK To Feature Scott's Decision To Enter Rehab

On an upcoming episode of KUWTK, Scott decides to enter rehab. The episode, which will air January 31, shows how the Kardashian sisters, including Kourtney, felt about Disick at that time, reported Us Weekly.

"Have you heard that Scott's gone to rehab?" asks Kim. "He wants to really get it together and wants to go to rehab for a long time."

But Khloe revealed that she had heard at that time Disick was partying.

"I hope he stays and actually, like, does the treatment," Kardashian declared skeptically.

And dishing on how Kourtney felt about Scott, both sisters agreed the 36-year-old wanted to stay apart from him.

"I mean, I think she's been really distant from him and just wants to keep her distance," revealed Kim.

"Yeah, she's over it," added Khloe.

[Photo by Dimitrios Kambouris/Getty Images]