Rihanna Flashes Barbados In See-Thru Bikini Top

Rihanna nipple slipEverything was bikini as usual when Rihanna hit the beach in her native Barbados yesterday ... until she took a dip in the ocean.

Rihanna's orange bikini top turned transparent in water ... but the singer didn't seem to mind, splashing around without a care in the world.

Feels so good being bad.