Repeating myself....please excuse...
You cannot change the wording of contracts people are already signed into...Marriage contract is between a Man and a Woman....we signed it. I will not enter into the same contract as Men and Men, Woman and Woman....there is precedence> not a lawyer, but dont you have to consider what has already been signed into and called within the confines of the law? If they change it to Same-Sex Marriage...we will then have to change, because I will not sit in the same contract, union as homosexuals....We will have convenant ceremonies those before God. Covenant, committment before God, who does not recognize homosexual partnerships....but only to say they are an abomination.
I am not a lawyer either, but in my real life work had to do a lot of legal interpretation, so I think that I can pretend to answer like one in the absence of a real lawyer (one who I just pinged).
My guess would be that a real lawyer would say that any changes in future contracts (marriages) with new parties (men & women, men & men, women & women) does not change the terms of your legal contract (marriage). In other words, that you entered into a legal marriage when legal marriage required that only members of the opposite sex could marry, they would say that your marriage is legally unaffected by any future decisions the legislature might make re the rules for State sanctioned legal marriage.
Forgive me Kolokotronis, but that's what I meant about lawyers and politicians deciding what "a marriage is" -- it's like "casting peals before swine". The spiritual meaning of "marriage" is irrelevant in arguing law.