Like it or not, sex is something that will likely need to be discussed with teens and children repeatedly over the years. Sex and sexuality are everywhere in modern culture, so there is no way a parent can bury their head in the sand and pretend that their little, puberty-ridden angel is not being bombarded with sexual thoughts and curiosities.
Frankly, the Church does not have a great history when it comes to dealing with the very real issue of sex. Too often, children and teens spend their whole lives hearing that sex is evil, wrong and sinful but are given no real way to deal with the inevitable surge of hormones and sudden awakening of the biological drive to reproduce. Then, after listening to endless sermons about the evils of looking twice at that really attractive classmate, they are expected to suddenly and miraculously have fulfilling sex lives when they marry.
Change the conversation about sex by actually having a conversation. It may not be the most pleasant topic to discuss with children and teens, but if parents do not talk about sex with their children, those children are going to learn about it from other sources. Many sex education programs in schools are little more than a joke, and no child is going to ask honest questions about sex in front of all their classmates. That leaves them looking for answers in other places, and no parent with any sense wants other teens, television shows or, God forbid, the internet, to be their child’s primary guide when it comes to sex and relationships.