I have been spanked in public, as recently as a month ago actually, hehehe. We were in the great state of Maryland in a town in which neither of us had ever been to before, and might never go again to, and we were walking around the mall.
I don't exactly remember what I said to him, but I was being quite cheeky. I was headed into Clairs to buy some hair bands as I was making my cheeky comment, and out of no place, my seemingly rather quiet and reserved doctor/boyfriend, stopped in the doorway of the store, reared his hand back and spanked me 4 or 5 good hard swats on my fanny. It was a Saturday afternoon, the mall was crowded, everyone in the area looked.
I was a little embarrassed, and I think he embarrassed himself too, and I also think that both of us were shocked he did it, lol. Heck, I'm still shocked.
The people around us who saw it actually either smiled or laughed. One guy gave him a huge thumbs up. They all knew we were playing.
So yes it was public, very public, and it was really fantastic. The only thing that would have made it better is if he had pulled me over his lap, lol. But that's probably a bit of a stretch, lol.
I hope he does it again, lol, and soon!