bateman and aniston s characters develop an unlikely romance. sex addiction that we cannot change. recovering in the sex addiction world? yes. which isn t going very well. well, baby steps. she s making the effort. reporter: aniston says playing this kind of role was freeing. goes against every fiber of my being, yes. it s completely fun. dream job for any actress to play that monster. have you ever done it in a dentist s chair? no, i ve always wanted to nail my dentist, but he s a man. is it hard to come out with those words and not crack a smile? usually those happen through rehearsal. you get those little giggles out of. reporter: who is the biggest practical jokester? there weren t any cut-ups on our set. no clooneys.