Justin Bieber & Kourtney Kardashian Keep Heat Amid Dating Diddy's Son Quincy: Sexy Selfies Deny Baby Rumor [Pics]

Justin Bieber apparently gave Kourtney Kardashian a wake-up call when it came to the joys of dating a younger guy. At 36, Kourtney was the mom of three and had just split from baby daddy Scott Disick when she first hooked up with the now-22-year-old pop star. But Kardashian quickly heated up that hookup and had so much flirty fun that now she's found yet another younger man to satisfy her needs, a source told Hollywood Life.

Kourtney has been dating Diddy's son, 24-year-old Quincy Jones. And in a hint that someone's feeling competitive in the love department, her dates with her new boy toy came at the same time as her former beau Scott Disick, 32, was seen with his 20-year-old girlfriend, Christine Burke, who resembles Kendall Jenner.

"Kourtney's no punk. Gone are the days where she's going to sit around the house, crying and worried to death about what and who Scott's doing. Never again," revealed the source.

Kourtney Kardashian is single and happy to mingle.
Kourtney Kardashian is single and happy to mingle. [Photo by Jason Merritt/Getty Images]Kardashian has vowed to turn 2016 into the year where she was fun, and in Kourtney's mind, being with young, handsome guys is the way to achieve that goal.
"This is her year and she's going to do what makes her happy and being around young and hot men, full of vigor and vitality does just that. Quincy's sexy. She loves that face of his his hair to die for. He's fun to be around and he has a vibe that Kourtney's feeling."
The same source also feels that it's Disick who is to "blame" for having Kardashian so focused on dating younger guys.

"It was him who taught her that surrounding oneself with the younger species adds a pep in your step. And she's loving how her step feels these days," added the insider.

As for the Biebs, Kourtney still believes. But Kardashian is making it clear that she's enjoying her freedom to date and party after years watching that Scott didn't overdo the party scene. Without her role as "babysitter" for Disick, Kourtney is having fun, and she made it clear during her most recent evening with Quincy, noted the Daily Mail.

Kardashian has remained in the background when it comes to flaunting her fashion choices. But just as Kourtney has recently discovered the world of dating again, Kardashian also has stepped up her style game.

With her sleek physique, Kourtney has become a fan of sexy fashion mixed with relaxed, California casual chic, such leather leggings paired with a navy trench coat. And just like her sister Kim Kardashian, Kourtney also has become discovered the joys of flaunting her style choices on social media.

As for her new boy toy? Quincy owes his name to Quincy Jones, the music industry's legendary figure and his godfather. As the son of Sean Combs (Diddy) and Kim Porter, Quincy has grown up in the entertainment industry, who like Kourtney he knows how to mingle.

Kourtney Kardashian flaunts her fabulous figure.
Kourtney Kardashian flaunts her fabulous figure. [Photo by Frederick M. Brown/Getty Images]Quincy is making a name known for himself as an actor, model, and singer (feeling competitive, Justin?). He also dated Kardashian in December.

And that's where it gets interesting because it also was in December that Kourtney was spotted leaving Bieber's hotel at 4 a.m. without her bra, according to Hollywood Life.

Kardashian was seen at a club where Justin was partying, followed by her appearance at the Bieb's favorite hotel, the Montage in Beverly Hills. Her 4 a.m. exit boosted the reports that their hook-up had gotten much hotter.

All of that evidence has led to rumors that Kourtney is pregnant, with Justin as the baby daddy, as The Inquisitr reported. However, Kardashian has been faithfully posting some sultry, very revealing selfies that show a flatter-than-ever tummy.An Instagram post's worth a thousand words of pregnancy denial?

[Photo by Frazer Harrison/Getty Images]