He looks at you deviously. Then he pulls out a cup and puts it on the table aggressively as he proudly exclaims:

I'm gonna eat this glass!

He then proceeds to open his mouth open and smash his head onto the table causing his face to stretch like a cartoon character, and also completely putting the glass cup into his mouth. He then proceeds to chew the glass with his mouth open unfazed by any pain he might be suffering.