My 3 year old son caught me off guard today...

I was changing the baby's diaper in the van when we had stopped to do an errand. My son says to me 'mommy where is Catherine's 'peanuts' (yes, that's what he calls his private area)? I responded with 'only boys have that part.' Then he proceeded with 'what do you call the girls part?'

I'm thinking to myself I can just hear it now I tell him what the girls part is called and then he goes around saying it or 'discussing' the difference between girls and boys. I didn't want that to start happening yet...he's only 3 can't it wait a couple years? I mean it's bound to happen at some point, but I'm really not ready for that right now, so I just said 'son, now really isn't a good time for us to be discussing this topic.'

Was that wrong? Any ideas on how to handle this in the future would be greatly appreciated!