slapping back a girl is not a good idea. i remember back in the day i was driving in the car with me gf.. we had a dispute.. and all of a sudden she slapped me while i was driving. i remained cool, pulled over and said her "get the fuck out of my car". without any words she got out of the car and went by foot to her home. of course, then on her way back she called me and apologized.. i gave her a ride