Izabel Goulart Rocks Skimpy Bikini on Beach Outing with Fiancé Kevin Trapp

Izabel Goulart seems more into white sandy beaches than a traditional white Christmas … living it up in the Caribbean with her fiancé.

The model and former Victoria’s Secret Angel soaked up the sun and surf in St. Bart’s Saturday … flaunting her curves and toned tummy in a tiny white bikini.

Goulart grabbed a paddle and played some games with friends on the beach … running across the sands and smacking the yellow ball back and forth with the crew.

At one point, Izabel had to chase a ball down and bent over to pick it up … leaving little to the imagination when it came to her pert backside.

Goulart’s future husband, Paris FC Goalkeeper Kevin Trapp, looked ripped in just a pair of swim trunks … proving the world’s most popular sport certainly keeps ya fit.

BTW … Goulart and Trapp aren’t the only big-name stars on the island this time of year. Heidi Klum and her husband, Tom Kaulitz, are also enjoying some fun in the sun on the island — with Klum even ditching her top for a little skinny dipping.