A way to greet people, by pushing out your chin as far as you can and smiling, then shouting ah steeve in the most nerdiest possible voice. It started as an inside joke but has spread across where we live and is still spreading outwards into the world.
An example of what to say to someone and back to someone when doing or recieving the steeve face
bob *walking up to tobi pulling the steve face*- "AH STEVE"
Tobi *doing the same*- "STEEVE"