Kourtney, Khloe Kardashian Party on Stage at Billboard Music Awards 2016 Afterparty, Hang With J. Lo: Details

Kourtney and Khloe Kardashian hang with J.Lo, Jessica Alba and Meghan Trainor in Vegas
 Courtesy Khloe Kardashian via Instagram

Having a wild time in Vegas! Kourtney and Khloé Kardashian were thrust into the center of the action on Sunday, May 22, when rapper 50 Cent pulled them up onto the stage at the Billboard Music Awards 2016 official afterparty at Drai's Nightclub.

The Kardashian sisters, who had been partying previously that evening with Meghan Trainor and Jessica Alba at Jennifer Lopez's hit Las Vegas show, didn't want to miss out on any of BBMA madness — so they headed down to the Vegas hot spot to party the night away with the stars.

Dressed in supersexy little black dresses with revealing cutouts, Khloé, 31, and Kourtney, 37, were having a pretty low-key evening in the club, chilling out at a table with pal Malika Haqq, before 50 Cent started his performance.

"Khloé was smiley and turning and letting fans snap cell pics of her," our insider tells Us Weekly. "She would smile and ham it up, turning her head and posing."

Bow down to the queen @jlo

A post shared by Khloé (@khloekardashian) on

But once 50 Cent got on stage, everything got a bit wilder! The rapper pulled Floyd Mayweather and Wiz Khalifa up with him between songs, and then, after performing "P.I.M.P.," he invited the Kardashian sisters to join them all too.

The sexy reality stars became a little bashful! "They were pretty reserved," our insider told Us. "They just hugged 50 and Khloé waved to the crowd. Kourtney grabbed Khloé's hand [and] they shook a couple of the other guys’ hands. 50 invited Malika too, making her feel included," the source continued.

It’s been quite a weekend for mom of three Kourtney, who has left the kids behind to enjoy some girls' fun in Vegas. On Saturday, May 21, the sexy Kardashian showcased her awesomely fit body in a pair of leather shorts and a leather strapless bra top, as she partied with pals at the grand opening of the Jewel Nightclub at the Aria Resort & Casino.

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