Where this rib fits

 

Who the crown fits,

Let them wear it.

None of these crowns fits,

and I'm weary.

I'm a square peg among circles.

Where do I fit?

Small feet,

In which pair do I fit?

I'm the rib that's never been found-

bruised and pecked. 

If you please, tease and laugh.

Pain is not enough

For you, the game has just started.

I'm bone of no bone,

Flesh of no flesh,

Crushed by every bone,

And eaten by every flesh.

Where does this rib fit?