I made counter point in another thread that I still feel answers your "logic" well:
So your argument is based in part on evolutions role in physiological functionality? Ok, the penis exists for procreation withthe vagine. Sounds good to me. But what about all of our other phyiologcal characteristics that have simply not evolved at the pace of our civilization?
Hair is designed to retain warmth, in our society we now tend to depend on clothing of our construction for warmth. Does that makes clothing immoral since it defies our present state of physiological evolution? The same can be said of finger nails, etc. What I'm getting at is that you're justifying your position of denying equal rights to a segment of our popultion on the basis of evolutionary necessity; we weren't designed for anal sex. Well we were designed to ride in air planes for 18 hours either, does that make it immoral?
I'm fine with you electing not to engage in homosexuality, I'm of the same persuasion, but exactly why is it YOUR business what any other adult does with themselves provided you or anyone isn't HURT by that activity? Shouldn't that be left to the relationship between them and god? Are you God? If so, i repent and I will say anything you want so you don't banish me to !heyal! but otherwise know your role and back off.