NewlyGranny: I have a memory from somewhere of a woman, not a teacher, perhaps a nurse? coming from a session with secondary age girls - KS4 - completely rattled because she had told the girls sex was supposed to be pleasurable for them too, not just for males, and it was complete news to them. Some of them had wept.
I remember an article in the Graun about this (back when their women's pages carried actual women's issues rather than dick pandering dressed up as faux feminism). Terrifying.
My constant message to DS now he's secondary age is "wait till you both feel comfortable, only have sex when you actually like each other, and make sure both of you are enjoying it and are really comfortable."