Getting back to justice, to be "appropriate" the rights granted to any behavioural minority group, should not be seen to have a retrograde effect on others, as in allowing one minority the right to redefine the rules of the game.

OMG! A definitive statement from Akenaton! Will wonders never cease? He's totally incorrect, of course, but at least he's saying something real. Here's what's wrong:

Justice is never inappropriate. Gays are not a "behavioural" minority, and it wouldn't matter if they were, since religious folks (a real behavioral minority) are specifically granted the same rights as everyone else, and it's also illegal to discriminate against them. There is no evidence for and no sense in the statement that gay marriage will have any retrograde effect on others. How would that manifest? The reason we have a Constitution in this country, and whatever it is that the UK has that's similar, is so that the rights of minorities are not trampled. Redefining the rules would be changing the Constitution to allow discrimination against minorities. Marriage has been redefined many times throughout history, and means different things in different places. There is a pressing legal and societal need for gay marriage now, and allowing gays to get married is less of a redefinition than our government telling two people who want to become a legal unit that they can't.