Kourtney Kardashian Bares Her Belly Amid Justin Bieber Hookup Rumors

Kourtney Kardashian showed some skin in LA on Wednesday while dropping off her daughter, Penelope Disick, and niece, North West, at their ballet class. The outing comes just a few days after the mom of three celebrated the shared birthday of her sons, Mason and Reign, and commemorated the event with a supersweet Instagram snap of the boys. Kourtney also celebrated herself on social media this week, sharing a sexy photo of her naked backside from a recent photo shoot.

The reality star has been garnering even more headlines than normal lately thanks to rumors that she's been hooking up with family friend Justin Bieber. A source confirmed the reports to Us Weekly, saying that Kourtney, 36, and the 21-year-old singer have been carrying on a fling "for some time now," adding, "Every time Kourtney and Justin are together they're extremely flirtatious. They text each other all the time." Another source told People that Justin "has had a huge ego boost" from their hookups and isn't at all bothered by her ex Scott Disick's feelings about it. "He brags about how hot she is. He is happy while it lasts. Even if she is using him to get back at Scott, he couldn't care less." Keep reading to see Kourtney's latest skin-baring outing.