I will get combative if anyone hits me on the top of my head, but I enjoy being slapped in the face by my fiancee if it's unexpected and private...especially when she follows it up by grabbing my balls and squeezing a little.
I love being slapped in scene. Thighs, girly parts, face. Especially accompanied by some dirty growled words or something. It's definitely I turn on for me and we limit it to try and prevent visible marking.
I'd rather my Mistress not hit my face, but if I deserve it- I deserve it and it'll happen.
Though we have a rule about leaving marks that can't be covered by clothing since I still have to be presentable at work and home