Sexual morality is the relationship defined by consenting adults, with respect to each individuals' boundaries.
I don’t think it’s sexually moral for a man to beat a woman simply because she consents and it makes him horny.
Take away the “it makes him horny” part. It’s then ok for a man to beat a woman because she says she consents?
This is a hill I am willing to die on. I told my ex it was ok for him to hit me, that I WANTED him to hit me, but he wouldn’t do it outside of sexual gratification. Funny how the lines aren’t so blurred when someone isn’t getting off sexually. (Why am I crazy for wanting to be hit for non-sexual reasons? The idea of anything being ok when you “consent” falls apart when you consent for non sexual reasons.)