I guess that this is the fifty shades of the pole.

Rothbardian_fanatic

There is "chinko", "chin chin", "chinpo", "chinpoko" and "penisu". The last one would be used more for serious situations (in a hospital for example), whereas the first three are used interchangeably.
"chinpoko" sounds more juvenile.
"chinko" and "chin chin" are, I strongly believe, interchangeable. Even though if you look at the dictionary it would be written juvenile word for "chin chin".
So feel free to use any, for jokes I recommend you "chinpoko".

john_doe

ideasfromtheedge

Let’s Learn Japanese with Sensei: おすすめ

cryotosensei

I think that this is the diminutive term for penis in Japanese. Usually used for children and spouses. There is another term for adults, I think.