Under your axioms, it may be equivalent, but I think they're mistaken.

Orientation is not a choice, and is orthogonal to identification.

I believe that same-sex relationships can be as profoundly fulfilling, enriching, and pro-social as heterosexual relationships.

That marrying a straight woman with a gay man is profoundly unfulfilling for both.

And that denying a class of people something so profound, freely enjoyed by everyone else, and which does not harm anyone else, can indeed be seen as inhumane.