This week, the fashion set partied hard on both coasts. In New York, Joan Smalls, Harry Brant, and Marina Abramović joined Riccardo Tisci to celebrate the launch of his new sneaker collection for Nike, while, uptown, Karlie Kloss, Derek Blasberg, and Erin Heatherton showed up at the Park Avenue Armory for a private performance by The xx, hosted by Burberry. Jessica Hart threw a celebratory dinner for Michelle Ochs and Carly Cushnie at the Rose Bar, and Leandra Medine hosted a lunch at Bergdorf’s for jewelry designer Sabine Ghanem. Meanwhile, in L.A., Kate Mara showed up at H&M’s Conscious Collection dinner with her stylist, Johnny Wujek, and the CFDA celebrated the 2014 Fashion Incubator Los Angeles Showcase with Timo Weiland, Jonathan Simkhai, and Irene Neuwirth. Click through the slideshow for a peek at the best moments from this week’s parties.