Kourtney and Kim Kardashian are living it up in Punta Mita, Mexico with gal pals, in honor of Kourt’s birthday. While everyone looked smokin’ in their respective swimwear, it was Kourtney in an itsy bitsy, teenie weenie red string bikini that stole the show.

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KOURTNEY MARY KARDASHIAN 😍🔥🔥🔥 #kourtneykardashian

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The mom of three wore a Minimale Animale The Lucid Bikini Top ($85) that barely kept her covered. She’s showing a *lot* of underboob. Considering her top is a string bikini that she could have adjusted on her own, it seems like this is an intentional styling method.

Trend or not, the 38-year-old is definitely pulling this tough look off. She even complemented it with a pair of red circle shades and a simple gold cuff.

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KK 🔥🔥🔥 #kourtneykardashian

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Kourtney was also spied pulling off the same look in a black bikini while she lounged on a yacht. We’re definitely sensing a theme here.

Meanwhile North and Saint’s mom Kim wore a printed vintage Dior bikini with green, yellow, and red trim that she accessorized with layers of necklaces, huge hoop earrings, and Pucci sunglasses. There’s no underboob here, so perhaps its just a Kourtney trademark.

Who knows if Kourtney’s look will actually take off as a trend, but hey, it’s her birthday and she can wear what she wants!

What say you? Yay or nay? Let us know on Twitter @BritandCo.

(h/t Refinery29; photo via Kevork Djansezian/Getty)