OMG!!! My son who is 17 just asked me the same question the other day..lmao!! I had to explain how the old time douches were... Too funny.. How old is your nephew?
What a cutie pie! They get so big wayyyy too fast. PS: Tangie don't count on dad for that stuff. Half of what they tell um is inaccurate to begin with, lol. Do what I did...get a good book with lots of pictures. Break it down over like 3 days (boys one day, girls another, std's the third). Pics make sooo much easier because there is little eye contact. Don't feel bad. I gave my son the complete novel version and his girlfriend was still preg. when he was 15 and she was 16. Don't wait too long. Like I said, they grow up wayyy too fast!
I spoke to my son when he was 12 but he was also hanging with an older, tough crowd and was already very mature. Guess ya have to assess his maturity level and go from there or when they start asking very specific questions.
unless you want him thinking babies come from belly buttons after a long night of drinking and making out, lol. and NO, a girl cannot get preg. from a toilet seat!