I repeat: this is not a question of 'rights'. 'Rights', as such, do not exist; what is actually extant is the ability of individuals to behave as they will and make that will a right - the right to Will in such a way that other men cannot actively defy it.
In the case of gay marriage, gay individuals have every 'right' to conduct a ceremony as they wish, and they are then as validly married as the Traditionalist couple before the altar. And the Traditionalist couple has absolutely not the slightest 'right' to deny them that.
To argue otherwise - to suggest that 'cultural norms' are capable of overriding the individual Will - is to slip into collectivism.
Before the individual, civilizational routine falls away like discarded chaff; God Himself quakes in fear.