There is no sexual "perversion" available to us, that was not once considered a normal, moral, perhaps even necessary act by someone else.

Barring the things like electro-genital stimulation that haven't been available long enough to have wide experimentation. Even then, if you look, you're likely to find advocates and denunciations as soon as the possibility for a new perversion opens.

you may not find a horse attractive, but then you're not ascending to the Throne of Ireland, either...