Teeny tiny bikinis! Exotic beaches! Count down The Hills star's sexiest days in the sun in honor of her birthday
Credit: Ethan Miller/Getty
Updated: Monday Jun 14, 2010 | 06:15 AM EDT
By: Andrea DeSimone
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Taking a break from being the bikini babe in the family, Audrina picks a monokini while sister Casey goes for a red-hot two-piece to accent her tattoos for some poolside antics in Las Vegas.
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