Kara DioGuardi shocked American Idol viewers when she stripped down to her bikini while performing onstage during the show’s season finale.

The 38-year-old singer-songwriter joined ‘Bikini Girl’ Katrina Darrell ( with noticeably bigger curves) for an epic sing off. The pair performed their own rendition of Mariah Carey’s Vision of Love.

To everyone’s surprise, at the end of the song, Kara unzipped her dress to reveal a black string bikini she had on underneath.

“What a stomach, Kara,” Ryan Seacrest commented.

Oh, and Kris Allen won.

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