"It can't be done, Bill.

You can punch a gent for cussing you, or stepping on your foot, or crowding you, or sneering at you, or talking behind your back, or for a thousand things.

But back here in a crowd you can't fight a gent for laughing at you.

Laughing is outside the law most anywheres, Bill.
It's the one thing you can't answer back except with more laughing.
Even a dog gets sort of sick inside when you laugh at him, and a man is a pile worse.

He wants to kill the gent that's laughing, and he wants to kill himself for being laughed at.