We never would have guessed that these two would be an item!

Jaden Smith, 14, and Kylie Jenner, 15, are dating, according to Us Magazine. "It's new, but they've been friends forever," a source tells the mag.

On Sunday Jaden and Kylie were spotted on a lunch date at Caffe Nero in London's Piccadilly Square, but prior to that Jaden was kicking it with Justin Bieber, who celebrated his 19th birthday on Friday at Cirque du Soir.

Bieber's entourage apparently got into a squabble with club security because Jaden is underage (the drinking age in the U.K. is 18), and while Bieber denied that was an issue, a source tells the mag that it definitely "caused problems." After the argument, Bieber was photographed stomping around in the street without his shirt on, and a few hours later he tweeted, "worst birthday."

Biebs later added, "Sometimes u just wanna vent and not be quiet. I love my fans though. Just gonna chill with friends. London shows this week. It ain't always easy but is what it is. Gonna stay focused." Hopefully he's not mad at Jaden!

Kylie Jenner is going to be front and center at New York Fashion Week to catch all the latest collections. Over 300 designers will be showing off their goods!

The 14-year-old reality star, holding on to mom Kris Jenner, left her NYC hotel rocking leather pants and pricey Christian Louboutin heels.

Can't wait to see which runways her sister Kendall will be strutting down. Young, gorgeous and filthy rich!

Hope everything's ok at the Jenner household.

Bruce Jenner held on tight to 15-year-old daughter Kylie while the two left an afternoon meeting looking quite somber.

It's been awhile since we've seen the teenager out in pubic without makeup. Nice to see young Kylie looking her age.

If she's having a bad day, good thing she has dad by her side.

Kylie Jenner is following in the footsteps of her famous older sis, Kim Kardashian, by going blonde ... for the day, at least.

The 14-year-old reality star struck a pose, alongside a gal pal, rockin' lighter locks while sporting a red beanie. Shortly after, Kylie Tweeted, "Brunette Foreverrrrr."

Nothing like a bathroom photo to show off your new temporary look.

For the second night in a row, Kris Jenner took her daughters to the Justin Bieber concert at the Staples Center in Los Angeles, and the ladies dressed to the nines for his show.

Kendall exposed her midriff and wore a pair of skintight jeans, and while Khloe kept her outfit on the casual side, Kris gave her teenage daughter a run for her money with a pair of leather pants and a wild animal print blouse. While the clothes aren't exactly age appropriate, we can't hate -- she def doesn't look 56 years old!

You let your daughter out of the house like this, Kris Jenner?!

Kylie Jenner hit up the Justin Bieber concert at Staples Center last night with her momager, and the 15-year-old was definitely not dressed her age in red leather pants, a see thru tank top and a visible lacy bra. She must be learning how to grab people's attention from her older sister Kim Kardashian!

The Keeping Up with the Kardashians star is rumored to be dating Australian singer Cody Simpson, who happened to perform along with The Biebs last night, so we would bet Miss Kylie went backstage. Ahh to be young, rich, and rubbing elbows with the world's biggest teen pop stars!

Chord Overstreet, Real Housewives of Beverly Hills star Kyle Richards, Jason Bateman, and others also came out to watch JB bust a move.

Kim and Kris Kardashian, along with pal Jonathan Cheban faced off against Bruce, Kylie and Kendall Jenner and Kourtney Kardashian in Miami's Dragon Boat Festival race, on Saturday.

"Going for the gold," Kylie Jenner Tweeted early yesterday morning. Kim followed up with: "Ready to row #teamDASH."

So who came out on top? Team Jenner took top prize ... not much of a surprise -- after all, Bruce IS an Olympic gold medal winner!

Now we know why Kendall Jenner, 16, and her sister Kylie, 14, are so comfortable with their bodies. This bikini photo of their mom, Kris, says it all!

The Jenner ladies chilled poolside while celebrating the 4th of July holiday, and in the process, showed off a little skin.

Kendall Tweeted, "outside alllll day, so many freckles #freckleyken'"

It's tough to keep up with those Kardashians Jenners!