Kylie Jenner, Hailey Bieber Show Off Bikini Bods Lounging on Miami Yacht

Kylie Jenner was looking mighty fine and living her best yacht life -- ditching mom duty for designer bikinis alongside fellow mama Hailey Bieber as the two soaked up the Miami sun.

You have to check out these pics -- Kylie was a total smoke show, flaunting that bangin’ bod in a teeny black bikini while catching rays aboard the ultra-luxe UTOPIA VI -- interestingly, the same name as her ex Travis Scott's new album.

Kylie was strutting around the deck like it was her personal runway, soaking up every angle of the sun -- perfect relaxation the Friday before walking the blue carpet at the Met Gala Monday night as both their men -- Justin Bieber and Timothée Chalamet -- skipped the event to watch sports instead.

Meanwhile, Hailey was all about that lounge life, stretched out in a red bikini and bucket hat, locked in on getting that perfectly even glow.

Clearly, the girls -- including Kylie’s ride-or-die Stassie Karanikolaou -- were in full chill mode.