Kourtney Kardashian Shows Off Fit Physique in a Barely-There Bikini

After her ex-partner, Scott Disick, stepped out with his Kendall Jenner look-alike girlfriend, Christine Burke, on Wednesday, March 16, and after rumored ex-fling Justin Bieber posted a sweet throwback photo with Selena Gomez on Instagram on Saturday, March 19, Kourtney Kardashian showed the boys what they're missing by posting a very revealing photo on Sunday, March 20.

The 36-year-old reality star put her sexy curves on full display while laying out in the sun with a barely-there bikini. “Sunday funday!” she captioned the racy photo.

After a busy few days visiting Universal Studios with the kids and attending her brother Rob Kardashian's 29th birthday bash, the mother-of-three spent her Sunday relaxing in the sunshine.

Her baby daddy, Disick, was also in attendance during Rob's party after recently saying Kardashian will always be his family. “I mean she [Kourtney] always be family to me and probably the person I love the most in the world," he told Us Weekly on March 18. "So even though we’re not together, we’re still close and it’s still nice to be around each other.”

Kardashian's super sexy photo was posted just a day after Bieber drove Jelena fans wild when he posted a throwback picture of him kissing the "Same Old Love" singer. Bieber and Kardashian were spotted together numerous times but the duo never confirmed nor denied the romance rumors. One tabloid even claimed that the reality star was expecting a baby with the 22-year-old pop star. HollywoodLife reported that the rumor of Kardashian’s pregnancy took off when Life & Style magazine published a story that quoted a source close to Kardashian and Bieber.

“Kourtney’s already admitted to friends that she and Justin have been intimate, and she hasn’t been with Scott in a longtime, so the math is pretty clear," the source told the mag. "It would have to be a Bieber baby.” The insider added that Justin wants to be a father and that he ‘is telling friends that the Kardashians are already like family.”