There is ample evidence that sex is a part of a normal, healthy life.

Being run over by a car is unhealthy at any age.

Dante hinted at the monkey studies - I am thinking he means the ones that showed that monkeys who do not engage in sex play at an early age are socially crippled for the rest of their life - but there are many reasons to believe that sexual repression in childhood is harmful. Then there is all the evidence of the positive role sex plays among bonobos.

Of course we would like any such sex play to be engaged in responsibly - but that probably means more adult involvement, not less. Children don't generally learn to swim or ride a bicycle from their peers, but from adults. There's a reason for that.

But your arguments do remind me of the importance of reminding society of all the positive aspects of sex. As long as society equates sex with being run over by a motor vehicle, they will be bamboozled into wanting to prevent it.