I was left in the dark until 5th grade sex ed. Until then, I didn't even know that males had anything to do with producing children, I thought it was a coin toss thing that either happened or didn't (and my mom wondered why I was so confused when I couldn't understand why she was telling me it's a sin to have a baby before getting married
)
When my brother was 15, my father had been dead for a while, and my mom thought it might be a good idea for me to talk to him about it. My exact words were these:
"In her typical clueless state, mom thinks that you're still an innocent, sheltered kid, and wants me to give you [finger quotes in the air] "the talk." I think she wants me to give you the basic idea of how
tab a fits into
slot b and the whole bit about sex before marriage being evil and a ticket to hell. So since you pretty much know the mechanics of it and don'ot believe in hell, I'll just tell you two things that I want you to remember: Always wear a condom, and learn to give good oral. That's all you need to know."
He doesn't talk about it much, but he's assured me that he's been following my advice