It makes no difference to me if my next-door neighbors are male/female, male/male, female/female. If they love each other and want to commit for a lifetime, why shouldn't they get married?
I do not see what possible impact the marriage of same-sex couples could have on male/female marriage. (And before you go "quoting" the Bible on me, be sure you want to abide by all those other things that are abominations. Like seafood.)
Look inside yourself & see if you can find any real reason to be opposed.