This whole thing can be settled really easily.
Get the government out of the marriage business. There is absolutely no reason or need for it. If courts would simply honor contracts like they should, then there is no reason at all for the government to be involved. At all.
If you have ever paid attention the me at all, then you know that I think virtually everything should be legal. I am very pro-freedom. However, some people need to realize that everyone has a stake in this issue. As long as our system works the way it works, if the government recognizes a marriage as legitimate, then other people are legally obligated to treat it as such even if they view it as illegitimate. This is true. You may not like the fact that some people don't view it as legitimate. I don't care. Those people who want to marry are no more, nor are they less, important than the ones who don't want to recognize their marriage.
This is an issue where it is not possible to give everyone their freedom as long as the government is involved. If PersonX can force a law making it illegal for DudeA to marry DudeB, then the Dudes have less freedom. If DudeA and DudeB can marry and use a law forcing PersonX to treat them as married, then PersonX has less freedom. The rights of either group is not more important than the other group's rights. However, if we have no law, either forbidding it or forcing people to recognize it, then PersonX has the freedom to believe and behave as he sees fit and the Dudes have the freedom to believe and behave as they see fit. Win, win.