Heavens, what's next? Interracial marriage?
</Sarcasm>
Wasn't too long ago that many people considerered that to be immoral and subject to legistlation. I wouldn't be too suprised if some forum members actually still thought that way (though I doubt they would admit their bigotry quite so openly)
It was considered immoral by uneducated people. For instance, the Catholic Church has always allowed interracial marraige, never condemning it. A man and a women produce a child. However, two gay men can't make a child. Therefore, the point of marriage is completely missed.
In addition, English Law never banned interracial marriage- it's really a 20th century thing. In the south, many slave owners would marry their slaves.
