It does have to be factored in also that teens now are much more bombarded with images and ideas of sex and sexuality than those of my generation.
Almost everything in advertising alone, for example, seems targeted on sexual attractiveness and rejection of authority. Broadcast morality is permissive and 'role models' (tho' I choke on the term) are promiscuous, their sex lives fodder for the media mill.
It's no wonder, therefore, that those who are growing up in such an atmoshpere are curious and experiemntal earlier than we were - especially when discipline of them is legally prevented.
If we want to have a prayer of salvaging our societies, such that we may have some stability in our old age, these trends have to be reversed.
Otherwise ... selfish dystopia here we come.
You're right. You can't turn on the tv today without seeing someone in bed, someone kissing, etc. I think that in addition to that, many people who view female stars as their idols, ie: Jamie Spears, Brittney Spears, etc. see them with kids and think, "Well, if they can do it, so can I!"
This is yet another reason why the parents need to help their kids seperate the fantasy from the reality.