Celebrity Kourtney Kardashian Turns 38! Take a Look Back at Her Best Bikini Moments By Anna Hecht Anna Hecht Anna Hecht is a London-based writer who has covered all things fashion, health, and celebrity news. She currently is an Editorial Director and manages commercial content. InStyle's editorial guidelines Updated on April 18, 2017 @ 07:00AM Pin Share Tweet Email Trending Videos Photo: AP Images Happy birthday to Kourtney Kardashian! Today, the oldest of the Kardashian sisters turns 38. With her spunky sisters by her side, Kourtney and the rest of her family have dominated pop culture since emerging on the reality TV scene back in 2007. Perhaps what we love most about the Kardashian clan is their tendency to take things to the next level. Between their jet-setter lifestyles, extravagant parties, on-screen family drama, luxury vacations, and endless projects, the family has a go-big-or-go-home mentality. And, we aren't referring to their famously full derrières—though they frequently make headlines too. Speaking of behinds, this birthday beauty is not without her family's signature Kardashian curves, which she frequently showcases on Instagram. In barely-there bikinis, Kourtney regularly snaps her incredible post-baby bod since having her three kids: Mason, 7, Penelope, 4, and Reign, 2. To see for yourself, we rounded up Kourtney's best bikini moments in the photos below. 01 of 07 Curves On Curves 02 of 07 Itty-Bitty Black Bikini 03 of 07 Look, Ma, No Hands! 04 of 07 Sunny Selfie 05 of 07 Poolside Pose 06 of 07 Stars in Stripes 07 of 07 Toned and Taut