After listening to this joke, I was so happy that I couldn't keep my mouth shut.

Happy from ear to ear. "Happy from ear to ear" is a rhetorical device called exaggeration. Used to describe a person who laughs from ear to ear. This sentence uses exaggerated expressions, and through vivid description, it enhances the strong sense of laughter and joy. This rhetorical device is often used in literary works or spoken language to enhance the effect and interest of expression.