Mary-Kate Olsen and Stefano Pilati are seen sharing tongue at the YSL afterparty for the Met Gala Premiere, at the Bunker, New York. Pilati is an Italian fashion designer. Since 2002, he has been the head designer of the fashion house Yves Saint Laurent. Mary-Kate Olsen is an American actress, producer, author and fashion designer. She made her career debut in 1987 alongside her twin sister Ashley Olsen in the television series Full House. There are no reports of them dating each other. The photo is taken by Olivier Zahm.