Tricky subject this isn't it.

As for teaching sex education to the kids, early as you think they can understand what you're talking about is best to ensure full understanding when the time comes for them to experiment.

They will, with or without the education or parents consent, but the one's who know shit all about it will get pregnant or catch something nasty before the one's who've been told the pitfalls of sex activity.

As for what is the acceptable age, well, underage is difficult to quantify, in UK the legal age of consent for straight and gay is 16.
In other countries it's as low as 13.
In the US led internet land, it's 18, far too old to be considered a sensible age to learn about sex.
But controls are needed and a line has to be drawn somewhere I suppose.

pops........