Vintage couture dealer Didier Ludot is the de facto king of the Palais Royal, so when he decides to dress windows, pop a cork, and stay open late, many of his fashionable neighbors—Marc Jacobs, Stella McCartney, and Acne among them—follow suit. That’s what happened last night as he ushered in fashion week with Infidèles, an in-window exhibition of vintage clothes shown alongside furniture by sculptor Maryam Mahdavi (pictured, with Ludot). An exquisite 1923 “Nuits de Chine” embroidered dress by Patou, a 1990 Dior gown by Ferré, a 2006 Marc Jacobs jacket, and a 1960 black Balenciaga gown surrounded the artist’s red lacquered “Chair de Poule” (literally, “goosebumps”) table with a black coral-like sculpture fanning out from its top. In the next window, Mahdavi’s gold-tipped “Arbre aux désirs” kept company with a stunning 1967 Féraud fishnet chain dress decked out in medallions and lockets. “I bought that years ago from the daughter of a jeweler who made the dress for Féraud,” Ludot explained. Would he sell it? Oui, but not to just anybody. In fact, next to it stands a gold leather and grosgrain jacket by Karl Lagerfeld for Chanel from 1991 that had sold just that afternoon—to Danielle Steel. (The ’55 Dior gown that Reese Witherspoon wore to the 2006 Academy Awards was a Ludot buy, too.) Next door at Marc Jacobs, meanwhile, the Champagne flowed and windows were toasted, too. Jacobs filled his with ballet slippers on loan from the Paris Opéra Ballet, a dance inspiration of the current collection.