Olivia Palermo

Nude beaches aren't always as cool as they sound ... just ask former MTV star Olivia Palermo, who learned that lesson the hard floppy way during a trip to the Caribbean.Palermo -- who starred on the reality show "The City" -- hit the sand in St. Barths Wednesday with her fiance ... and even though…

Fashionista Olivia Palermo became famous on "The City," but it was the hills of the buck ass naked woman behind her that got all the attention in this pic taken on a nude beach in St. Barts Thursday. Despite rockin' an itty-bitty orange bikini, Olivia was not breast in show.