kids growing up

Our kids spent 4 days at Grandma and Grandpa's farm. Had a great time (so did the parents -- it was so quiet and tidy at Shady Hall.) When we went to pick up DD and DS they told us all about G & G's new rooster and hens and how they got to pick eggs, usually 2 or 3, every morning. As we were ready to leave we heard a commotion at the edge of the wheat field. Seems Rusty Rooster was "chasing" Penny Hen and he "caught" her at the edge of the field. Well DD thought it was hilarious. She said "Rusty chases his girls all the time, then he likes to jump on their backs just to annoy them!" When I looked at DS he had an odd grin on his face -- like he KNEW what was going on. He didn't say anything, but I know he knows that I know what he knows. In a quiet time later this week, I tried to ask him about it, but he put his hand up and said "mom, I know what you want to talk about, and I really don't want to have this conversation."
DH and I have always been upfront, if the kids ask those kinds of questions -- honest, but not graphic. On a few occasions DS has asked about a word he heard. Once DH said, "I can tell you son, but it's about sex." I think DS was about 8. His response was, "I don't think I want to know then."
It's not that I don't want him to know. I do wonder about his sources and their accuracy.
The part that has me ruminating on this issue is that it means he's reached a milestone. He is growing up. I remember the days when he got most excited about a "twuck," I am not ready now (nor will I be even in 5 years) for when he is enthused about girls instead.