Kylie Jenner, Kourtney & Khloe Kardashian Waist Train Together!

Kylie Jenner looks surprised as she leaves Sugarfish through the backdoor after dining out on Sunday (December 13) in Calabasas, Calif.

The 18-year-old reality star stepped out amid the rumors that her pal Justin Bieber and her older half-sister Kourtney Kardashian are hooking up.

The rumors began over the weekend when the pair was seen partying together. Sources have begun coming forward with information that they began hooking up back in October when they were first seen out together.

So far, no information has been confirmed by either party or anyone in the Kardashian/Jenner family.

Kylie recently posted a photo of her with Kourtney and Khloe Kardashian, showing them waist training.

“Posted up with my babes getting our waists right with @premadonna87 @waistgangsociety 😎” Kylie captioned the photo on Instagram.