Cristobal,

I’m not a Kantian, and I don’t invoke sacredeness. I come from a virtue ethical perspective. If my position commits me to say that causal sex among homosexuals is unvirtuous, so be it. I don’t see any difference between homo- and heterosexual relationships.

The tricky part of your suggestion is “harms no one.” I argue that using other people for personal gratification does harm our own character. I can testify that I definitely felt the harm the few times I’ve engaged in that behavior.

And I don’t buy that sex, the most intimate act a human being can engage in, is in any way equivalent to playing chess.

But of course reasonable people may disagree here.