The sex education in the school is not about spiritual understanding verse whatever it is you want teaching to include. Sex simply is sex and much of their teaching excludes so much it is misrepresenting it. What they teach is like if someone didn't know anything about a car or what it does and went to be educated. So they learn about pistons, and gas, and avoiding accidents and say now, you are educated, without being told that a car is something to get you from one place to the other, etc.
Sex is a physical means for two people to become one in marriage, for the first overall view of it. That is not spiritual understanding, that is nitty gritty down to earth what it is. Song of Solomon gives a lot of it. If you take out what some call the spiritual part of it, you get something that isn't sex at all, it is a fleshly synthetic attempt at it and always fails in some way.