I recently heard one that just made me shake my head.
The concern is that Gay couples will produce Gay children.
I laugh at this because the Straight couples have been doing a 100% job at producing only straight children.
Some people tend to forget the basic rule.
Make sure brain is in gear before engaging mouth.
I have yet to find any reason whatsoever to deny any consenting adults to be joined in the term of marriage and reap the benefits the government gives such clusters.