If you hit the guy, it's your ass no matter what happens. So you need to settle on the classy response- the open-handed slap.
If you happen to have a glass of something, then even better- you throw the drink in his face. Nothing that man can say or do will get him out of that. Plus, it's nice and legal.
Rules for that-
1: No hot drink. Burns=lawsuit.
2: Nothing bottled. Trying to shake out a bottle of anything is embarrassing and will just kind of splash around, getting yourself wet as well. Plus, you've made the hand-job gesture. Now you're in deeper.
My ladyfriend and I have a pre-arranged rule: no fighting ever. The only loophole is if someone calls her the C-Word. Then if I do not fight him, I am a coward and will face an even more severe beating later.
That's my word.
C