Kourtney Kardashian has never looked hotter!

The 37-year-old flaunted her fit and fabulous figure in a bright yellow one-piece during a beach outing in Miami with ex Scott Disick and their three kids, Mason, 6, Penelope, 4, and Reign, 21 months.

MUST SEE: North West Wears an Itty-Bitty Bikini During Trip to the Beach With Her Nannies

The brunette bombshell, who frequently documents her intense workouts on Instagram, showed her baby daddy what he's missing — though recent reports claim the duo has been "hooking up" in secret.

Scroll through the gallery below to see photos from the family-of-five's sun-filled vacay!