As I recall, in G. Lucas' film "THX-1138" there was a television channel that featured nothing but a robot beating a naked person with his billy club. When I first saw this, I laughed out loud at the obvious satire of our society's need for sex and violence in our entertainment. I had much the same feeling after seeing this film.
At first the film seemed like a competent look at how two people in love want to explore every aspect of each other's bodies. The initial mild S&M just seemed like a logical extension of that exploration. But when the beatings bordered on mutual self destruction, I immediately saw this as lampooning our society's need for ever increasing "kicks" to satisfy our insatiable lust for ever increasing degradation of the human body.
The director suckered us in and punched us right in the gut! Bravo!.