Well, I don't know how this pertains to religious studies, but I would sat that sex education, like most social skills/ideas/etc, a very significant amount of one's knowledge about it comes from ones social circle. For example, all the immature middle schooler talk about sex in grade/middle school (and high school to some extent I suppose) may not explicitly be considered education, but it is something that can highly influence young people about sex. One thing that I know from my experiences is that when talking about certain subjects that may not be public-friendly per-se, oftentimes we use metaphors, and with sex education specificly, almost all conversation about sex is done with some degree of abstraction or metaphor usage. On that topic, it is imperative what kind of metaphor one uses. For example, the most common metaphor I have heard is baseball, or some other kind of sport. To me, this metaphor is oppressive, for it teaches young people that sex is exactly like a sport, in that there is ALWAYS a winner and a loser, it always has to be done in a specific manner, with specific types of people, and other types of archaic misconceptions. A better metaphor I learned from a TED talk is pizza. For example, you can whatever you want on your pizza, oftentimes you don't just have pizza, you consult with whoever you are having pizza with about what kind of pizza to have, any kind of person can have pizza, you can have pizza at any time, as opposed to baseball, which only happens during pre-scheduled baseball games, and experimenting with pizza is not stigmatized, while if a baseball player decided to run the bases backwards, they would likely be punished, etc.
I highly recommend everyone to watch the TED talk by Al Vernacchio on the topic.