Arterton, 23, who co-star"s with Gyllenhaal in the upcoming movie Prince Of Persia: The Sands Of Time, plays the part of a sixth century princess, while he the prince. “There"s an unspoken no-tongues rule on set. But I got so carried away, it kind of slipped out," Contactmusic quoted her as saying. “Everyone said I was lucky to be snogging (kissing) him, but he''s the lucky one!" she added.