A reader posted this as a comment. I thought it worth sharing.
As early as I can remember, I was royally sexually turned on by the merest thought of spanking. Puberty hit and it got worse. Then I had to admit to my 12-year old self that spanking girls - Hitting! Girls! - turned me on. I felt I deserved and would wind up in prison. So revolted by the thought I buried any desire of actually spanking any woman - ever. I didn't want any women to think I was a dangerous, sadistic freak!
Fast forward about 17-years. My new girlfriend "tricks" me into spanking her. Started light then saw she was enjoying it. Increased it a bit and still no protest. Put a hand between her thighs and her entire body arched as she sucked all the air out of the room. A little more spanking and rubbing and she jumps off my lap, pushes me back and mounts me, DEMANDING I fuck her and fuck her hard.
The orgasms we both had were memorable; to this day, memorable.
Afterwards, I asked her about the spanking and if she liked being spanked. Quietly, she admitted that she did.
Me, softly: "Why didn't you tell me before?"
Here it comes....
"I thought you would think I was a freak and never want to be with me."
And there it was; neither of us wanted to admit to the other what we had both wanted. And as the story goes - Bacall - "...this was the beginning of a beautiful friendship.”