I'm sorry to say, but you must be living in a ulturnate reality to be able to say "what people do behind closed doors" It is no longer such in America, sexuality is massivly common place. I fear that our society will collapse because of it. We are breeding races of ignorant, arrogant, microteens... I'm not joking. My 6 year old sister goes around acting like she is 14, singing and listening to rap, and not to mention has already cursed. And it isn't just my sister, you can see it all the time. Its a horrible debasement to the United States.
If you honestly think this, then I guess the Greek civilization was tantamount failure in your eyes. A difficult thing to say of course seeing as how most modern philosophy and science we owe in a massive way to the sexually free Greeks.