The Metropolitan Museum's annual Costume Institute gala was this evening, and basically every fashion-obsessed celebrity out there showed up in their red carpet finest for NYC's biggest party of the year.

While A-listers like Julia Roberts, Katie Holmes, Beyonce, and JLo dazzled in their couture gowns, in my opinion the biggest surprise of the night was the arrival of Mary-Kate and Ashley Olsen. Not only did the twins choose to wear Diane von Furstenberg dresses to the event (which seemed like an oddly safe choice to me), but I actually saw one of the usually-stoic girls grin. Say cheese, Ashley!