Same principle. If you don't talk about something like that, it is more awkward to talk about when you do.

The more I read about, the more puzzling it sounds.
Seriously - I think being killed or beaten is, at the VERY least, a lot worse of a fate than having sex or being kissed 0_o.
Then again - there are/were places where premarital sex was A-OK but EATING TOGETHER (before marriage) is/was considered highly indecent. YMMV...
What's hilarious is the fact that people (and kids in particular) are EXPECTED to giggle at such things. Especially at the implicit ones.

Kind of like people are supposed to have sex and not shy away from something so natural as if it's evil incarnate.

To be honest - it's not being natural that makes it good... Violence is as natural as it gets.
Assuming that things can be good because of either utility, pleasure or virtue - I'd say it's the second reason. As such - one would have to prove that there are negative aspects/consequences that outweigh the positive side... Not likely.

It's a matter of perspective, I guess. And one constantly influx. (sex between consenting adults is good, sex between kids who are far too young isn't. Violence in self defence versus violence for the hell of it and so on).
If anything, an act in itself isn't classifiable as good or bad, more the intent behind it.

Heh, that's why I always say they should make something like driving licence for sex - even thou it sounds ridiculous, it would solve oh so many problems :D

I'm assuming it would be a written exam and not a practical one?

You can get A LOT of things in the Czech Republic that are hard to find in Poland very easily.
Except a native SMILE. LOL
Religiosity can't be to blame here, but what is true in quaint towns in Europe, the States and the world over is that kids WILL experiment. If there is any embarrassment or complication for them to procure the right tools in their community biology WILL take its course. European countryside and the bible belt do not always stock such things in their gas stations, or in self serve machines.
If you're 15 and thats where you're at, going to the neighborhood pharmacist is out of the question. And if you're daddy is conservative Catholic than raiding his sock drawer produces nothing. The original poster isn't all wrong to prejudge this if they know the area.
The kids story about the game reminds me of the girl who "fell asleep" while getting her face tattooed!! Parents wish to believe the most ridiculous outside elements are the cause for their child's mistakes.

What were the rules about cunnilingus?

All of that you pointed out, about Trobriand Islands especially, is a matter of perspective. Within that culture, children having sex is normal and acceptable (so it seems) whereas in most other places, it isn't.
'Good' and 'bad' are they labels we put on things to justify actions through some sense of empathy. You can say, "it is good that the child killer was executed" or "it was necessary". A matter of perspective, and/or character.
As far as intent, I was never implying that consequences don't matter. They very well do, to haphazardly go through life doing things and purely saying it was done with the best of intentions is BS. You might have good intentions, great. But if it fucks up, shoulder the consequences. Going as far as saying that intent is the only thing that matters is a little extreme. ;)