Underneath her layers of couture, Ashley Olsen has been hiding a seriously sexy bikini body!

The fashion designer, 25, donned a mismatched black, red and yellow bikini top with black bottoms in Maui, Hawaii Wednesday. Later that night, her twin sister, Mary-Kate, was photographed arriving back home in L.A.

Though Mary-Kate continues to act, with recent roles in Beastly and The Wackness, Ashley has no desire to appear on camera ever again. "We worked non-stop until we were 18. Then we decided to take a break and go to school -- and that was when we decided to question whether we would carry on in entertainment," she told ELLE UK in April.

PHOTOS: Mary-Kate and Ashley Olsen through the years

Ashley continued: "It was time to step behind the process. I wanted to work on other things. It doesn't mean I'm not interested in Hollywood; I like the way it operates and the people who are involved and the sense of possibility. But if I ever do get back in, it's not going to be as an actress."

This article originally appeared on Usmagazine.com: See Ashley Olsen's Slim Bikini Body!