To me, the answer to this question is very simple, and you get it by answering a simple question. I posted that simple question on this board a while ago... and exactly nobody replied.
Do you masturbate/orgasm to the thought of spanking in any form (being spanked yourself, spanking someone yourself, watching someone be spanked, etc)?
If you do, guess what? It's sexual. No matter how much you tell yourself it isn't.
And if you don't... I cannot understand why you would be drawn to spanking if you don't, so closely tied to my sexuality is my spanking fetish... but if you can honestly say you do not EVER think about spanking AT ALL when orgasming, then it isn't sexual for you, I guess.
I wonder how many people actually fit that description.