Hell, imagine the ads! Every couple would produce one:
"Bill and Susan are good, God-fearing people who eat healthy and pay their taxes..."
"Bill and Susan live together in sin, and it could be in your neighborhood. Bill and Susan slaughter neighborhood pets and keep a crawl space in their house where they molest and torture girl scouts and paperboys. Vote no on Bill and Susan."
When the slippery slope argument is exhausted, many turn to the idea that marriage is for procreation. But when did intent on procreating become a prerequisite for marriage? Do you have to prove that you intend to have kids in order to get married now? When you go to get your marriage license are you forced to impregnate your future wife right there in front of everyone? What about elderly and infertile couples? By that I mean can they be married, not should they have sexual intercourse in front of large groups of people. Either way, I say YES!