A
do-do usually refers to an immature penis, but it can and is used to also, as a
pejorative, to identify or describe the
shrinking or always very small penis of an older or elderly white man.
Come on, Bobby, stand next to the toilet like Daddy and aim your
do-do, right in the middle, try to hit the toilet paper.
I am
sorry honey, Grandma is too tired to play with
Grandpa's do-do, you play with it.