I did not teach him that!

SO, there was Dustin laying in our bed having a nice chat with his sister Danielle whom we haven't seen for awhile. Ben was relaxing under the covers beside him.
"Daddy, I'm rubbing your tummy!" Ben remarks.
"Oh, thanks Ben that feels nice."
He continues to rub for awhile as Dustin continues chatting.
"Daddy, those are your nipples. You have little nipples."
Dustin chuckles as Ben points out his nipples.
"And mommy...." oh no here it comes "mommy, she has BIG nipples. Right daddy, mommy has big nipples!"
"Well, Danielle you're hearing it here first hand."
How he somehow obtained this sort of information I have no idea. Well, women do naturally have bigger nipples than men. And it's not as though the kid has never snuck up on me in the shower. I guess it's more humorous to me than embarassing or I wouldn't be posting this on the internet for thousands to potentially read and laugh.
To us what would be humiliating or even hilarious, to a child it's just a basic anatomical fact. Men have small nipples and women have larger nipples. It's not funny, it's a fact. Right? Right?
sigh.