What is Smash My Face?
1.
a phrase that can be said to encourage someone to fight you. This line means that you are inviting that other person to take a free swing at you before you begin the brawl.
Depending on the size and strength of the person you are fighting, sometimes you really will have your face smashed saying that, just like a cookie.
"Come on, gaywad. Smash my face!"
See
