I agree with Apexx. you should catch the kid who says it, but only when they're one man up so there's no witness and it's only your word against his. and then when you've caught them alone punch them in the nose as hard as you can. if they try duck then, if you can, catch them on their way down with a knee/kick(depending on how close they are) in the face. when you have them dazed you can punch them in the eye/throat or take them down and punch them in the solar plexus repeatedly (don't smash them in the breastbone too hard/too many times or you could find yourself doin a life sentence lol). when you've finished with them tell them that you'll do it again if they ever fuck with you like that again.