Yeah, I knew the twist as well, thanks to someone's status on Facebook. Grr. It was on my list of films to watch for ages and then I read the girl's status and was thinking "No... NO! Must unsee these words!"
I watched it anyway and enjoyed it though. Pretty f*cked up.
I'm on a bit of a foreign film kick at the moment (In the hopes of becoming even more pretentious!)
Anyway anyone who enjoyed the weirdness of this would probably enjoy the strangeness that is 'dogtooth' a fabulous Greek movie from about 2008. No real twist but defo competes on the f**ked up scale. (Don't watch if nudity or sexual activity offends you)