In his essay It’s Necessary for the Scene, American Playwright David Mamet explains why no play or movie he writes or directs include explicit sex scenes.
Mamet is no prude. He cut his teeth in the theatre, working in and around that last great institution of vagabonds and players, excess and fornication.
No, what he’s getting at here is something more important than a hopeless moral stance.
“When we see the scene of simulated sex we can think only one of two things: 1) Lord, they’re really having sex; or 2) No, I can tell, they aren’t really. Either of the above responses takes us right out of the film.”