Sex ed is of course a short form for sexual education. In Swedish "Sexualkunskap" or "sex-och samlevnad".  We in Sweden are supposed to be very open and straight forward with the subject. Some might think too straight forward.
I remember that I was shocked when I was new as a teacher, almost 20 years ago and found some old (70's?) "Pogo pedagog"  (the name of the company is hilarious, don't you think?) slides for sex ed showing a family taking  a shower together, but read the two last sentences here in an old sex ed book I found, and one get an idea what people were thinking back then:
In the same book I found this:
Apparently your fantasies are so wild they MUST remain a secret since they causes you to be ashamed if you would ever tell anyone about them...well...anyways...In the book they do talk about shame a lot. For example you should NOT be ashamed to masturbate. But mentioning "do not feel shame" on every page is in my opinion a way of saying that it might actually not be so natural after all...why else all of these encouraging phrases about it being natural and nothing to be ashamed of...almost like the writer needs to convince everybody, including himself. This was the sexual education our parents got. Poor them.