Well then, that's just absolutely terrible.
Why do you want gay marriage to be a crime?
You can't call a dog's tongue a dog's tail, and magically make the tongue the tail. Similarly, you can't just call something marriage and by calling it so make it so. Traditionally marriage has been defined as a covenant or agreement between a man and woman which by its very nature has the goals of procreation and the education of children, as well as the unity and wellbeing of the spouses.
Same sex marriage denies psychological, physiological, and biological differences between men and women that find complementarity in marriage. Same-sex marriage also denies the primary purpose of marriage, which is to perpetuate the human race through children (yeah, marriage is about keeping the human race alive, not about sexual pleasure, as many people today seem to think it is).
It is best for a child to be raised by a natural father and mother. Looking at the difficulties faced by orphans or those raised by relatives or foster parents, this point becomes clear. A child living in a same-sex "marriage" will always be deprived of his natural father or his natural mother.
Same-sex "marriage" also turns a moral wrong into a civil right. Bear this in mind: sexual behavior and racial treatment are very different. A man and woman may differ in height, weight, skin color, accent, wealth, and fame, but none of these things are impossible obstacles to marriage. Supposed "marriage" between those of the same sex cannot occur because of a biological obstacle that can never be removed. It doesn't matter what race, age, bodily shape, or wealth they have; by the fact that they are the same sex, marriage is impossible for them. Racial barriers: possible to overcome. Sexual barriers: impossible to overcome.
Finally, there is no such thing as a family in same-sex "marriage". If one of the "spouses" wants a child, they have to go through tons of artificial means. The natural tendency of same-sex unions is not to create families. Therefore it does not fulfill the basic reason for marriage, and furthermore deserves no state-sponsored rewards for marriage because it does not provide conditions for a stable, affectionate atmosphere beneficial to upbringing of children.
In short, same-sex is an imposter seeking to claim it is what it is not, and saying it is deserving of rewards that it is not. It is not even marriage by any traditional meaning. Understand: normal heterosexual marriage is the only way to perpetuate the human race; homosexual marriage by its very nature leads toward extinction. Do the math for yourself; it's not hard. Same-sex marriage is an imposter and furthermore an outright liar and abuser, intended or not, of children. And that is why I say it should be a crime.