Showstopper! Nicky Hilton bares her butt at Paris Fashion Week

Nicky Hilton got a little cheeky at Paris Fashion Week.

The 31-year-old hotel heiress hit the Atelier Versace show on Sunday and gave photogs a bit of a peep show as she headed up the stairs of the Palais Brongniart in a bizarre white dress with panel cutouts and see-through metal circles.

As Hilton ascended the stairs, the white frock rose up, which resulted in her giving the paps a full moon. The dress was clearly not meant for much movement and was at a constant risk for a wardrobe malfunction with the sheer panels. Paris Hilton's little sister polished off her risqué Versace ensemble with a set of white heels, a matching clutch and wore her hair down in loose waves.

Hilton is gearing up for her nuptials to banker James Rothschild on Friday at London's Kensington Palace, the home of Prince William and Catherine, Duchess of Cambridge. While we wouldn't recommend wearing a dress that shows underbutt, the bright white dress looked fabulous against her tan complexion.

And who knows – maybe Hilton is headed for a hot new trend. Perhaps sideboob is a thing of the past and next it will be all about the underbutt.