The Germans are just like the Dutch. I have lived in Germany for decades and raised my daughters here. My best friend, who is from Kansas, has slightly older children and told me what to expect when my kids reached puberty. I was shocked to hear that her son spent the night at his girlfriend's house and vice-versa. I remember asking her if her mother knew about that. "Absolutely not!" came the answer.

It's hard to break out of your cultural norms, but as you say, the Dutch and German attitude is certainly more realistic and healthier in the long run. I daresay it is America's Puritan heritage that lives on in the horror it attaches to sex.