I think I have a nice repertoire worked in. This can't be done on the first date, but is a good one on the second. Flirt around and pretend that youre long into a relationship and marriage, then say "we just got into an argument, so slap me"...watch the puzzled and confused look on her face...i say "it's ok, just slap me"...she very hesitantly reaches out and taps my cheek...i say "that was a love tap, i wanted you to slap me, not pet me"...she reaches out again and gives a more powerful swing. Depending on the force, you may want to ask a third time, if the second time was again too much of a pat. Looking for a slap that is not a lovetap but not serious enough to leave a mark. Then laugh it off "oww, that may leave a mark :)"
I would like a female opinion on what you would think if you were in this situation.