During an argument your partner slaps you hard across the face. What would you do ?

I’ve never been angry hit by a partner. I’m 6’1” and grew up working cattle on my parents farm, so I was pretty strong growing up and didn’t really get into any scuffles with other girls. I’ve only been hit by a man once when he called my beautiful black girlfriend at the time the N work dyke. I went up and spit in his face and he punched me. At the time, I sort of just stood their stunned but I tend to go PTSD rage now, so it’d be pretty bad.