He slapped me really hard and it made me cry

I just got done having sex with my SO and he was drunk so he kinda went too far and really smacked me hard on the face but idk why it made me super emotional and I let out a few tears during intercourse but I got myself together and then after we were done I just let the tears roll down and idk I felt weird.. hes slapped me before in the face during sex so it’s not the first time he does it and I don’t mind it.. if I did I’d let him know but idk I’ve never gotten emotional about it to the point where it made me cry.. has this ever happened to anyone?

Is it just my body’s natural reaction to getting hit?