SIENNA Miller has a thing for her co-stars. She was engaged to her former “Alfie” cast mate Jude Law, then hooked up with “Factory Girl” star Hayden Christensen - and now, she’s said to be in love with her “Edge of Love” co-star, Matthew Rhys. According to Cosmopolitan.com, the two have been “secretly dating for awhile. He is really into her but they have both been trying to keep it very quiet, only telling close friends.” Miller was last linked ...