Here's what I can tell you. I have three girls, yesh DH is sharpening knives a lot in preparation for them dating! Anyway, I was not comfortable hiding things and so they have had exposure to a lot of things. Since the oldest was born I would take my kids with me. Attachment parenting they call it. I was probably just not willing to leave them out of my life! They have gone to role play parties with me, the D&D and vampire kind, coffee houses, seen me host role plays at the house, gone to the theater with me when I worked there. Hosted dinners for other theater friends. So from the time they were able to go outside with proper clothing, they have been around people that were of different sexualities and relationship types.
When they were between the ages of 9 -12 they went to a camp with us for the summer where it was clothing optional. Among other things. THere were special things in place so kids weren't exposed to the super kinky but the weird? Oh there was no escaping it!
I started the sex talk when the oldest was 11 and the youngest was 8. Why? Kids aren't kids. I hate it I do, but there's little I can do about the fact that my elementary aged kids come home talking about friends that were mad at them for talking to a boy about a movie when they were going steady, or dating! Who dates at 9??!
So I suggest you start the sex talks! Keep it to what they will understand at their age. Then keep having it. I've had it I don't know how many times at this point! When I found out my oldest was texting grown men on sex chats her talks changed a bit. We still have talks. I'll go through the basics and then let the youngest go while I talk more mechanics with the older ones.
Nothing wrong with being curious and as far as I know, (all girls remember, though I've got nephews and raised my two brothers), boys can have wet dreams as young as 10 so yeah, there's going to be curious. I personally don't think you need to get into condoms and the mechanics of sex just yet. If you can, stall that conversation about oral, anal, diseases and what feels good versus what sounds good when you are writing horny messages to each other. It's not fun, and I've had it several times.
Doubt at his age you need to worry that far ahead yet. So, start with the basics. Guys, girls, different parts, what feels good, exploring your own body. So not old enough physically for exploring with a 'girlfriend' yet and definitely not old enough in his mind, soul, or heart. That's the toughest talk really. Trying to explain as they get older that no matter how adult they think they are, how intelligent everyone says they are, the heart and soul are just not up for all that sex entails.
oh! And answer questions honestly. Even if the honest answer is "I don't know." Or "I'm still figuring it out myself." That last one is powerful. After all, if mom and dad are still figuring stuff out how can they be expected to know it all!
Me: Late 30s pansexual poly.
DH: My husband of 19 yrs and father of 3 teen girls.
DC: LDR of +4 year