There's a lot of references to orgasm in the writings of Shakespeare's contemporaries. Ancient Egyptians had a very playful attitude towards sex, as evidenced by art and writing. Romans had recreational sex, aided by the availability of a natural abortion inducing drug. Also, quite famously, there is graffiti from ancient Rome admonishing a local resident to stop constantly going down on local women.

Recreational sex is a basic human thing, across cultures and across history. People who think otherwise are just demonstrating ignorance of history and culture. This is common among young people, who often aggrandize themselves by convincing themselves that they are the first people ever to discover [insert basic human thing here]. Much harm has come out of their activities. (Though this too is a basic human thing, and much fun has also come of it.)

Well, the Kama Sutra is said to origin from around 400 BCE.