My wife, daughter, son and I were out for an evening drive in the country looking for deer. Son was about five at the time. I pulled over and jumped out to take a pee. A few minutes after grtting back into the vehicle and resuming our drive my son asked me to pull over so that he too could go pee. He got out and was peeing in the ditch and happened to turn his head to see us watching him.
At that moment he yelled: "Stop staring at my bagina!"
Twenty-seven years later and we still laugh about that... and we still have no idea where he heard that term ( at least a variation of it

) at his age.