Son 3.5 year-old

Mom: Son, you are going to learn the letter 'N' next week, what subject are you going to bring and share with your class tomorrow?
Son: 'Nut !' Answered quickly without thinking.
Mom: do we have a nut for you to bring and share with your class?
Son (just had show and naked on his bottom): Here is the Nut! (simply lift up his penis...)
Mom (surprisingly): who has taught you that?
Son (calmly): nobody, I came up myself. and it is a coconut!