It was another late night of work for Sienna Miller yesterday in London. The actress dressed down as she left the theater where her new and well-reviewed play, Flare Path, is playing. She sported sneakers and a topknot as she made her way to a waiting car but stopped to sign a couple of autographs for waiting fans before heading home. Sienna has been focused on her latest role for the past several weeks and says she's hooked on the thrill of being on stage. She's also, though, making time to nurture a new romance. Sienna and Tom Sturridge have been hanging out together in the wake of her most recent split from Jude Law, and the two are quickly becoming one of the cutest new Spring couples with their cute pub and coffee dates.