I should’ve specified that I meant within the confines of the law. Specifically self defense.   If a girl or guy comes up to me and slaps me hard just once, and doesn’t engage further, it would not be self defense for me to strike them back (at least where I live).  There were a couple of times where one of my girlfriends got really angry at me and started punching me as hard as she could, repeatedly. One time was while I was driving and she was hitting my arms and body. I was allowing it because it really didn’t hurt, and after a few seconds she kept escalating and scratched me. At that point I could’ve smacked her asleep, but I pushed her back with my arm and got loud. Then I said “I’m gonna fucking hurt us both, watch this” and started speeding towards a light pole. Scared her shitless. If she hadn’t stopped when I pushed her back and raised my voice, I would’ve hit her to make her stop.   The other time she got on top of me while I was in bed fresh out of the hospital with a sprained foot, and she got on top of me and started gorilla smashing my chest and arms. Didn’t hurt at all, but she had every intention of hurting me, and kept going until I stopped it with my voice.  If she wasn’t my girlfriend though and did the same thing in both situations, she would’ve been smacked hard once, and punched hard after if she continued. If she got punched and happened to end up in a hospital, there should be 0 punishment.