Kourtney Kardashian celebrated her 39th birthday on April 18, but you would never guess it by looking at her steamy new photo shoot in V magazine. In the spread, the mother of three leaves very little to the imagination as she poses completely nude to promote her new collaboration with Kylie Cosmetics — and we must say, she looks pretty freakin' hot! "I think this shoot, using my collab with Kylie, was the perfect situation to try some new stuff," Kourtney told the magazine. "I've lately been in a mood to try more things with makeup and hair, and I personally have even more fun with it when I have a reason." Turn up the AC, and check out Kourtney's sexy photos ahead.