is penis a naughty word?

it wont' be,if u use it in a proper way but u usually wont' just go n' talk 'bout it right?

It is actually the "politically correct" way of saying the male reproductive organ. People can get grossed out or just plain weird if someone says dick, cock, or any other term used to describe the male sex organ. LMAO!!

It's just a word, like any other. =)

Only if used properly

Depends on how it is used, but it is a part of the male body like head and knee.