Your daughter would be obligated to marry anyone who raped her. The Bible is a questionable source for equitable law. Permitting gay marriage will destroy the institution for straight people. People will start demanding to marry their poodles or their maple trees. No one will get married anymore.
Marriage is an institution known in all cultures in all times.
It is not about to go away so easily. I can't imagine bride refusing her husband on the grounds she read in the newspaper that someone else who just happened to be male, shared a similar joy. Gay people fall seriously in love just like straights. In medieval times marriage was possible between members of the same sex. Clearly, it did not stop straight people from marrying then.