Watch the TV show 2 Broke Girls, I think its in the 9pm time slot. They discuss anal sex on almost every episode that I have seen. We rented a movie the other night with Jennifer Aniston, and anal was one of the jokes as well.
I notice that this is now acceptable territory for mainstream TV and movies when talking about doing it with women but its forbidden to discuss it when talking about men because it allows people to get a visual of what gays do to each other.
It makes one wonder how many men are kidding themselves about being heterosexual.