Video: Rihanna Celebrates Her Birthday in Hawaii Wearing a Tiny Two-Piece

Happy Birthday, Rihanna! The R&B singer is celebrating her 25th birthday in Hawaii. Check out the video for pictures of the Barbadian beauty sporting a tiny two-piece and a tattoo on her derriere. Do you think her on-again off-again boyfriend Chris Brown is partying with her? Tweet us @OKMagazine.

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