At age 16?? If you teach them 16 is okay, they may start at 13. In my book, 16 is much too young to be sexually active. At 16, they should be allowed to date in groups (such as dances.) At 17, they should be allowed to go on individual dates. At 18, they are young adults, old enough to start thinking about serious relationships, if they wish. Teach them they should wait until they are adults and married, and it is best not to marry too young. We know full well, in this day and age, they probably will not follow that advice, but that is still what we should be teaching them!
Look, they are teaching fisting to 1st graders, gay sex experimentation and all kinds of deviant shit.
If you think 16 is too early for sex, then pick an age.
My sex ed consisted essentially of what I wrote. A nun was the instructor. I lasted until I was 19.
Lighten up people, the genie has been let out of the bottle, we’ll never go back, short of a nuke strike and a rebuilding of the culture.