Pippa Middleton, the younger sister of The Duchess of Cambridge (aka Kate Middleton) and sister-in-law of Prince William, stopped by the Vanity Fair/Serpentine Sackler Gallery party last night, showing off her perfectly toned body in a feather-y Matthew Williamson creation. The event, hosted by Vanity Fair and Serpentine Sackler Gallery, was held to celebrate the […]