Human has been having sex since the dawn of mankind, using that as a way to reproduce ourselves from ancient. For thousand of years in history, some culture even created guidebooks for sex education. Kama Sutra in India, The Perfumed Garden (الروض العاطر في نزهة الخاطر) in Arab, a book written by Philaenis in ancient Greece.... just to name a few. Even nowadays, no mater what you think/believe or anything, physical needs has always been, and will always be inseparable of mankind, unless mankind evolve into some kind of machine.