The Birds and The Bees

When I came home yesterday D told me about a conversation that he had over heard between J and E. J wanted E to play house and be his girlfriend so that he could lay on her. I thought to myself...this is going to be a tricky one.
One day I took all the babysitting kids to the Library. We decided to rent movies. Unfortunately the romance novels with the pretty pictures on the front are right next to the movies. J and the boy I sit for were talking about the people on the covers having "Sex" I pretend not to hear them...just to see what they new about the subject. The conversation ended quickly with an outburst of laughter.
D and I make it a point to keep the X-rated stuff in the bedroom. We do kiss and hug in front of the kids to let them know it is natural and we love each other. Remembering the conversation in the Library and considering D's report I asked J what he was talking about.
I started out by telling him that he was not in trouble. I asked him about he conversation with E. He just kind of laughed. Remembering the Library again. I swallowed the lump in my throat and asked him if he knew what sex was. He smirked again and said "no" Apparently he knows that it is something that is very adult.
So he asks what is it? Here was my response...
"It is not something that is silly or bad. It is something that a man and woman do when they are married" (Hypocrite). J says "oh...why?" All I could think of was..."So they can have a baby." He comes back proudly with "So, you and Daddy are having sex now?!" Of course he would say that. "No" I replied "you just have to do it once and you will get pregnant."
I can't believe that I was having this conversation with him. I didn't want him to think it was bad or bad to talk about. I am hoping that he knows I am comfortable with the subject and he will be too. I am sure that some would say I did the wrong thing. I think that I did what was necessary...it just blows my mind that the topic is coming up already.