Most parents are clueless.
Remember that teacher's aide accused (falsely) by a Jr. High student of having touched her inappropriately?
The Freeper taliban had the guy hung, drawn and quartered before she confessed to having made the whole thing up.
The only thing more remarkable than the fact sex is everywhere is the universal denial, "My little girl never lies, and she would never do that!"...
Hey, I was a teenager once and I know what goes on. If I lock her away I don't have to worry about this stuff.