bigmac that's my 2nd least favourite reason for someone to be against gay marriage. Tradition. Basically the idea that we shouldn't try something new because that's not how people did it before and they felt no need to change it.
I think it's pretty flawed reasoning. Just to illustrate:
*just after marriage was invented*
Person A (gay person wanting to get married): Hey I'm about to marry this man
Person B: Nope, can't do that.
Person A: why not?
Person B: Marriage should be between a man and a woman. God said so and Bob is writing it down somewhere so people don't forget it.
Person A: Yeah bu-
Person B: No same sex marriage. End of.
*present day*
Person A: hey we appreciate the sentiment behind the whole "civil union" thing but it still doesn't feel like we're being treated equally
Person B: yeah well to allow gays to get married would mean that the meaning of the word would be changed
Person A: So? Meanings of words change all the time.
Person B: well that would go against tradition.