Frances:
We've been TALKING for years now. It isn't just "one talk" you have with your children - it's constant communication...
It's modeling behavior you want him to do...if you are single - no men sleeping over. sends the wrong message to your kids.
Tell him what's going to be happening to his body over the next few years. Wet dreams, morning woody's, etc. there are books on it - I'm sorry - I don't have them - but I know they exist.
When you see a racy commercial or show - or even on a game he might be playing - ASK him what he thinks about it. That can start the conversation....ask him about what happens on the playground - are boyfriends and girlfriends sneaking off to go kiss? See how he reacts to it...then get him to talk about what he sees and hears. Tell him what you expect.
Don't make it ONE conversation...make it communication over meals, don't make sex taboo...don't laugh - although it is tempting sometimes. We actually had a bout of "rainbow parties" on our school buses (not in ours but in our district - way south of me) and I asked my son if he knew what they were - no. What do you think it is? I told him what had been happening on some school buses and he said 'how disgusting to do something so personal on a bus" - that made me feel good. I asked - does this mean you have something to tell me? He said - eeewwww so not there mom!!!
It's okay to make it funny. It's okay to laugh about things. Modeling the behavior you want to see is the best with open lines of communication!!