"I hope this little display helps you realize my commitment to make this spanking, let's say, truly felt"
(judging by her selection, "truly felt" might be an understatement.)
"Since it wouldn't be fair you had all the fun, let's play a little game..."
(If by fun she meant ending with a throbbing scarlett bottom, I was surely about to "enjoy" myself. Gulp!)
"... I'm going to blindfold you, pick one of these and apply five smacks. You'll have to guess wich one I chose. Should you be right, I'll select the next implement. If you aren't, you'll get ten additional strokes, each time, until you give me the correct answer. If I use one of the three pairs exposed, I also expect to be told if the right or left one was applied, and any mistake will be treated with the same result as the previous rule."
Thanks to my memory, I did rather well while she held me accross her lap, except for the left or right nasty rule.
It got really worse when she had me bend over the edge of the bed, as I endured like a dozen of "penalty volleys" before acknowledging she was whacking my butt with a sandal she'd removed...
I could sense she was really delighted with her cheating trick!