Sex Education

Is on my mind at the moment thanks to technocrat.

So I am obviously for it, I don't believe anything has ever been gained by hiding something that is both useful and truthful to all who hear it. After all, we tell children from a very early age how dangerous knives are, and endeavour to teach them about their proper use as soon as they become capable of using them.
I'm not going to do old arguments to death though, so instead I ask a thought experiment of you: Suppose contraception was 100% effective. Suppose that either there aren't STDs, or even where there are, we have easy effective cures for them. I ask this now in the hope that one day both of these conditions will be met; I doubt they will be met perfectly during my life, but we may get close, so let's think about the impact of this to society.
If sex is risk free what do you teach teens/children about sex? Does it change your opinion on how we do teach sex education if that were the reality?
But which way does your opinion change? Does this mean we should teach about it more or less?
I can see arguments both ways, but if you truly do have sex without consequences then how does society change? Do we go the way of the bonobos monkey, do the swinging sixties actually return and this time include people outside of a tight social group in London? Or does life just carry on as it always has?
Most likely I see us continuing on our current course, England was recently found to have the most one night stands of anywhere in Europe, so this may well continue.

As for education, forewarned is forearmed; if you're talking about the body anyway...