Willis' risque skirt featured three large side-holes in the thigh area that displayed her bubblegum lingerie and part of her back side. She paired the item with a black crop top, a bejeweled minaudiere and strappy black sandals.
Other celebrities at the event included Cher, Stacy Keibler and Disney's Zendaya.
Willis, 25, is the daughter Demi Moore and Bruce Willis. She is best knows for her work in The House Bunny, Hostage and Now and Then.
2014: The Year in Music [PHOTOS]