Mine was a tender young thing who wanted to be spanked before sex. A fantasy of mine, I was pleased to do it. Naked bottom on my lap. My hand all over it, What's to decide!
Then after it had become part of our sex life, one day she said, "You're doing it wrong."
I asked her to explain and she insisted she couldn't explain, only show me, so she stood, naked and had me undress. She sat at the top of the bed with the headboard at her back, and had me lie over her lap.
As soon as I was in place, she clamped her thighs tight on my erection. Every movement was like being jerked off. She swatted my bottom, talking to me about how I'd disapointed her by not spanking her right. Then she stroked my balls in between swats.
More swats, still light; more discussion to which I had to respond; that careless placement of her hand when she wasn't spanking me.
Then asking me how many? No idea, so she made me count, starting over because I'd screwed up the count.
Tight naked thighs on my cock.
Then she got to a high number... and asked me if I wanted her to stop.
Panting, I said, "No..."