Questions of a four year old

Yesterday, I reminded my four year old that my breasts are my private area and he should not touch them hugging me.  He then asked why I had 2 "private areas" up top.  I did my typically I really don't have an answer of because God made girls that way.  He proceeded to lift up his shirt and say, but I don't have any private areas up top.  Because you are a boy Patrick............