I don't remember how young I was when I first figured out sex, but I got the talk (kinda) when I was twelve. My mum insisted on cleaning my room one day, found my porn mags, got extremely flustered and left the room. Five minutes later my dad walks in, drops onto my bed and starts leafing through the magazines. "So, you know about sex and all that stuff?"
"Yes dad..."
"Cool. Well, come talk to me if you ever have any questions."
"..."
There is something seriously unnerving about having ones parent read ones fap-material, I can tell you.