Another point is -- have you ever seen kids around their parents? They're absolutely appauled at seeing their parents' romantic life; they think it's disgusting to see their parents kissing or even giving them advice. Children/teenagers usually take advice and adapt from their FRIENDS and people outside their family. They rarely ever grow as their parents are, they don't want to even hear about their parents' sex life... So I doubt they'd learn from people they don't really even want to hear about when it comes to this subject.