Gird your loins!

These ultraskimpy, high-waisted “drawstring” bikini bottoms are sweeping Instagram.

Thanks to the suit’s skinny strap and the way the fabric’s bunched up, the internet has dubbed it the “loincloth bikini.”

Supermodels Elsa Hosk and Emily Ratajkowski are frolicking in the sexy look, which shows off everything from their hip cleavage to their so-called “Toblerone tunnels.”

Ratajkowski’s newly launched swim line, Inamorata, introduced the “Neptune” brief, while It girl labels Danielle Guizio and Minamale Animale are carrying their own versions of the sultry string bikini.

Tarzan chic, anyone?