***Per my experience, this is the best way to handle the topic of sex with pre-teens. I do not expect this to be acceptable to all parents, but I do highly recommend it. As with any advice you receive on the internet, it's up to you whether or not to accept it. With this advice, if you take it, handle it with care and caution, please!***

It's very true that your son probably knows more than you think he knows. I remember very well being in 5th grade which is about what grade your son is in and spending half a day in school separated from the boys and learning about my period, puberty and the developments I was facing in the next few years as a teenage girl. I recall being taught about tampons and pads and what they were used for and I remember hearing the guys I went to school with talk about what they learned about themselves. I didn't get all the details because we were all too immature and shy to actually talk about the details with our friends of the opposite sex, but I do know that they got a bit more information about some of the "urges" they were going to start feeling, while us girls generally just learned about our development and reproductive cycles. That same year, there was a big buzz among us kids over a used condom being found on the playground and many of the boys seemed to know more about what it was and how it got there than the girls did. That was over 15 years ago (I know, I'm young, but I also know how awkward your impending conversation is because I gave it to my sister, whom I practically raised from when she was born - I was 6 when she was born). I hear stories my friends tell me all the time about their little brothers/sisters, cousins and nieces/nephews learning far earlier than age 11 all they need to know about sex.

Talking to your boy now will help ease your mind that you've prepared your son to the best of your ability (and not anyone else's) to handle his changing body and understand his raging hormones a bit better when they start creeping up on him. Don't be afraid to speak to him openly about it and try not to use metaphors. ("The birds and the bees"? We all know what that phrase means, but when you think about it, it really doesn't make any sense.) Being honest with him now will help him feel more comfortable talking to you when you really want or need him to be honest with you. You'll respect each other more, which will help make his teenage years easier on you and him (not easy, of course, just easier).

Be mindful that other parents may not agree with an up front, honest and open approach (if that's how you choose to explain it to him) for no other reason than because he is still young. Explain to your son during your talk that if any of his friends want to know more about sex, they should ask their parents to talk to them about it. If they are too embarrassed to ask their parents, they can ask you, but make sure you tell them, should they come to you, that you will be obligated to contact their parents out of respect for them before having a conversation about it. Stress that they are not in trouble, but you'd like to help them make a natural but still uncomfortable conversation a little easier by explaining it with their parents' permission AND, ideally, in their presence, so that no one gets in trouble. In which case, explain to the friend's parents that their son has some questions about sex, a topic you've already gone over with your son, and you'd like to inform them of their son's curiosity. Then, leave the decision of how to talk to their son up to them - either they can talk their son on their terms or you'd be willing to explain it and answer questions, but not until they -the parents- are there to witness and be part of the conversation because it is their child. If the friend's parents decide they wouldn't mind letting you help them explain it, make sure you specify exactly how you are going to explain it so that they are prepared for how the conversation is going to happen if you take the lead. Encourage the parents to get involved and eventually take over. You only want to serve as something of a bumper to get the ball rolling (***if they need or want the help***). If they allow you to talk to their son without them being there, make sure both parents tell you separately and personally that it is OK for your to talk to their son and be very clear on what you will say. Clarify that you would be more comfortable if they were present for the conversation, but if they are insistent about not being there, then do your best to make it known and well-known that you have their permission to explain such relations with their child.

REMEMBER:
1. To be honest with your son. Don't use metaphors! They are just confusing!
2. Be understanding and empathetic.
3. Prepare yourself to not freak out if your son says things that shock you. Brace yourself, it's going to be difficult!
4. Keep your emotions and anxiety about your maturing child to yourself (at least while you're in front of him). In other words, maintain your composure as best you can!
5. ONLY discuss sex with your sons' friends when his/their parents are present. You could be implicated legally if you say anything to a child that isn't your own without their parents knowledge. This is for YOUR protection!
6. If your son's friends' parents tell you not they do not wish to be present, make sure you have witnesses that can attest to the permission you were granted by the friends' parents to explain it for them. Again, this is for YOUR protection.
7. Explain it in plain but decent terms. You do not have to be graphic to be understood.
8. Good luck!