And from that day forward the boy never left his room again 
I don’t think oral sex was invented. It was discovered.
Rae Dawn Chong. Didn’t anyone see “Quest for Fire?”
1025 views, but only 25 replies (at the time of writing). Is this some sort of record?
Well, the Romans knew of it. In A History of Private Life, Volume I, From Pagan Rome to Byzantium, Phillipe Aries and Georges Duby, General Editors, fellatio was one of the big taboos because they considered it a form of cannibalism (the swallowing bit) and a man was considered servile and weak if he gave a woman pleasure using his mouth.
Here is a copy of the Kama Sutra as translated by Richard Burton: http://www.thekamasutra.com/book/ From what I noted in the Introduction is that the book is dated somewhere between the first century AD and sixth century AD, with other chapters added later on.
So, it’s been around for a while, but I’m not where it first caught on.