Sienna Miller and Keira Knightley are preparing to shoot an onscreen lesbian scene, but off screen, the pair are more interested in tomfoolery. Taking time out between takes of romantic drama 'The Best Time of Our Lives', the Hollywood stars frolicked along the Wales beachside and giggled like schoolgirls.The stars are teaming up with actor Matthew Rhys for a steamy threesome scene - Rhys plays Welsh poet Dylan Thomas, who has two women competing for his love. Miller, who plays Thomas' wife, stepped into the role after troubled actress Lindsay Lohan pulled out over monetary negotiations. (*cough*couldn't pass the drug test *cough*) source
