Same sex partners, do not give up. There will be a day, when your civil right to marriage will not be prohibited because of your sexual orientation. I do believe that bigotry and discrimination are really born of fear, fear of something different from us. It is a sad thing, that in this 21st century we are still dealing with ignorance in the name of calling it a moral issue.
It's simple actually, we, none of us have the right under any circumstances to tell someone else how they will live their life. I have a gay brother. I can't imagine telling him that 1. he can't marry his partner of 10 years and 2. it's because it will cause my marriage to become less relevant.
We have come a long way from slavery, Japanese internment camps, allowing women and African Americans to vote and the LDS Church not allowing African Americans to have the priesthood. We just took a huge step backward.
I believe one day, our brothers and sisters who were BORN gay will be able to marry the person they love.