The pop star rocks a Star of David pendant during a night out with beau Isaac Cohen in Hollywood. Plus: Paris & Nicole, Sienna Miller and more

FRINGE FESTIVAL

Sienna Miller does the shimmy shake in a vintage dress at the New York premiere of her film Factory Girl on Monday. "I love the clothes!" the actress told PEOPLE about the movie's '60s-inspired wardrobe. "I haven't actually gotten to keep any yet, but I'm working on it."

The Factory Girl star later attended the movie's afterparty in her bloomers – what a minimalist! Weigh in on her daring look on our Off the Rack blog.