I always chuckle when I hear Christian right and other anti-gay types start in with the "They're trying to redefine marriage!" yelling, often while clutching a dictionary to their heaving breasts.
Because gay people like me can't exactly redefine something that hasn't been defined in the first place - at least, not the way they think it is.
The plain fact is, two people with opposite sex organs can saunter into a Justice of the Peace and create a legal civil marriage in this country with blood tests and signatures. That's it. Nothing - nothing - else is required.
Not love. Not a promise to procreate. Not shared living quarters. Not shared philosophies, about child-rearing or anything else. Not fidelity, of any kind. They don't even have to know each other. One penis and one vagina? You're in.
So I would suggest that if all these things are so important, if all these things are so crucial to the survival of the society, these people should start requiring them of their straight brethren. Physician, heal thyself, as they say. Because right now, straight people are disrespecting their favorite institution much worse than any gay person is able to.