Will Smith Slaps Reporter

The Ukrainian reporter tries to kiss Will on the lips on the red carpet and the actor angrily pushes him away and then backhands him across the face.

You can clearly see that Will is incredibly angry that the guy showed overt affection toward him. After Will slaps the guy, Will says, "He's lucky I didn't sucker punch him."

We're told the dude who kissed Will is a television reporter who often kisses celebrities -- it's his schtick.