Answer:
Three little letters. A paradox to some. The worse that it is, the better it becomes.
It's anything but amusing when this body part gets hit.
Take off my skin, I won't cry, but you will.
What is red and nailed to a wall?
Voiceless it cries,Voiceless it cries, Wingless flutters, Toothless bites, Mouthless mutters.
I am rarely touched but often held. If you are smart you'll use me well. What am I?