BOOM BOOM ROOM: Crowded, noisy and sweaty: The venue for today’s Lanvin show, a tent at the Tuileries gardens, had all the makings of a throbbing nightclub — one with a really great V.I.P. guest list, that is. Someone must have tipped off Anna Dello Russo, who arrived wearing a hat made from tiny disco glitter balls. Guests including Kristin Scott Thomas and Jade Jagger, with daughter Amba in tow, snapped up the fans left on their seats. Longtime Lanvin fan Julianne Moore came with her sister Valerie Wells. “We’re very close and we always have been, and it’s just nice to be able to be together for the weekend,” she said. Moore had just wrapped filming on “What Maisie Knew” and planned to start work on her next movie, “The English Teacher,” in two weeks. Orlando Bloom, damp patches growing on the underarms of his shirt, stood on the sidelines snapping pictures of his wife Miranda Kerr on the catwalk. Rachel Zoe wisely decided to leave six-month-old son Skyler with his nanny. “I won’t take him to shows yet. I think it’ll scare him, so he kind of enjoys the park and the Tuileries while I’m inside, then I come out and we go have lunch,” she said. It was just as well: In classic nightclub fashion, a waiter spilled a tray full of Champagne and pear juice cocktails all over the runway, moments before the show was due to start. It took several staffers armed with mops and a pressure washer to clean up the mess.