Ordinary love is mere animal attraction. Otherwise why is the distinction between the sexes? If one kneels before an image, it is dreadful idolatry; but if one kneels before husband or wife, it is quite permissible!
I have been to this point unwilling to sign on to same-sex marriage primarily because of my understandings of the traditional definitions of marriage. But I also think you're right that attitudes evolve, including mine.