Um. If someone showed up to protest my wedding without reason (say, a Jane Eyre thing where they wanted to point out my husband-to-be was already married)-- no matter the gender of my partner -- I'd be pretty pissed off.

Marriage -- as I see it -- at its heart, is just about two people who love each other dearly. Polygamy I'm a bit iffy on (mostly due to hearing about some bad examples), but it's supported by the bible, so that's another kettle of fish entirely.

Oh, and your complaint about JKR -- at least she's better than Margaret Atwood, who wrote a science fiction novel and made numerous statements saying it wasn't science fiction.