When is it OK to hit a woman?

I get so close sometimes but then I hold off because society says it's wrong. I believe if a girl says something stupid or just keeps talking, you should be able to smack her in the face. Not hard or in an abusive way, just enough to stun her for a second. I think it would do 2 things: 1) teach her to think before she speaks and 2) make her a better person. Now before you jump down my throat, I am not advocating woman abuse. I am talking a smack just hard enough to leave a hand print. The question is where do you draw the line and say this is acceptable and this isn't?