When did you have your first sex ever?
 

It's again anonymous. I see lotsa people have some complex feelings about it.

To bring some revelation in the topic. Statistically an average middle-class man/woman has his first sex between 18-21. It is pretty normal as that kind of people is quite busy when study in school. Their parents have more or less strict control over their personal life until graduation from the high school. Middle-class children literally have limited opportunities for courtship.