I'm sure there are rational arguments for keeping same sex marriage off the books. Not that I buy them, but I believe some opponents can make their case without being hateful or crazy. As arguments go, though, "Some five year olds will have questions about it," doesn't really make the grade.
If the definition of marriage is changed "our children will be taught a whole new way of thinking." What's that called, again? Oh yeah, "education." Shudder.