Lady Gaga Flashes Sheer Underwear in Slashed Dress

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Leave it to Lady Gaga to go from a custom Chanel design to a racy underwear-revealing look in a matter of hours.

Clad in a white tweed ball gown created especially for her by Karl Lagerfeld, the pop star, 25, made a grand entrance at the opening of her own "Gaga's Workshop" at Barney's New York on Monday.

"Getting ready for the opening of GAGA'S WORKSHOP at BARNEY'S in NY tonight! Wearing custom CHANEL by Karl Lagerfeld. #PinchMeMom #OhEmGee” Gaga tweeted before arriving at the ribbon-cutting.

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Later that evening, she changed into a black one-sleeve Stephane Rolland dress with a knee to thigh slit that showed off her sheer undies and unicorn tattoo for the International Emmy Awards.