That is the next paragraph in the decades old religious nut jobs pamphlet opposed to Same Sex marriage.<quoted text>
Why can't siblings marry? First cousins can in many states.
Siblings should be allowed to marry. After all, procreation is irrelevant to marriage. Right? right.
First you bring up Poly, then you move straight to Incest.
Ya ya... heard it all before.
You arent scaring anyone other than those that are so brain bound by religion they would not be in favor of same sex marriage anyone, that argument wont work on anyone with a pinch of intelligence left.
Your problem is you are playing to your constituency, those already opposed to same sex marriage, you wont convince any of the majority to oppose same sex marriage with that kind of tactic.
Same reason Republicans arent winning the presidency, they are playing only to their out of touch constituency and not the majority of voters.