I think you missed the day in school that taught a very simple life skill.
A hetro couple doesn't have to surrender all or part of their marriage for a same sex couple to have a marriage for themselves. My wife and I have a marriage, non church officiated, of 26 years. We won't have to give up any of our marriage to 'give' same sex folks marriage.
Next, you are quite stingy with words, a word can have more than one meaning and through time a word can change from meaning one thing to another.
If the gays 'stole' the word gay then who 'stole' the word f****t and made it a slur toward gay men? As I recall the word used to mean a bunch of sticks, or slang for a cigarette, now it is a slur for gay men... what happened, who was that thief???
Learn to share things you don't really own and can't stop others from using, be it a self descriptive word, or a term to describe a deep relationship with another in at the very least the eyes of the law.
I love the NSA. It's like having a secret fan-base you will never see, but they're there, watching everything you write and it makes me feel all warm and fuzzy inside knowing that I may be some person's only form of unconstitutional entertainment one night.