George R.r. Martin said this quote
“ I can describe an axe entering a human skull in great explicit detail and no one will blink twice at it. I provide a similar description, just as detailed, of a penis entering a vagina, and I get letters about it and people swearing off. To my mind this is kind of frustrating, it’s madness. Ultimately, in the history of [the] world, penises entering vaginas have given a lot of people a lot of pleasure; axes entering skulls, well, not so much. ”