Justin Timberlake and Mila Kunis, wearing a flirty Monique Lhuillier dress, were joined by their Friends With Benefits costar Patricia Clarkson and director Will Gluck at the Cancun Film Festival yesterday. It's been a jet-setting week for Justin, who flew to Phoenix for Monday's MLB All-Star game and then mingled with the world's best athletes at Wednesday's ESPY Awards in LA. During the show, Justin made another joke about his favorite beverage of choice, beer, and handed out an award alongside NFL player Aaron Rodgers. Justin's other new movie, Bad Teacher, also debuted at the festival over the weekend with his pal Cameron Diaz rolling solo for the photocall. Friends With Benefits is the latest comedy from Gluck since his Easy A. If you're having trouble telling the difference between Friends With Benefits and No Strings Attached, Buzz has the foolproof guide to help you out.