The same-sex marriage debate comes to Toehold

A response to my State of the blessed Union post attacks same-sex marriage thusly:

I wonder if I could be married to my platonic same sexed friend? Or do I have to start having sex with them in order for it to be condoned? Homosexuals simply do not have the right to change the definition of marriage that has stood for millenia; male and female. Homosexuality is no more an immutable characteristic; like race or gender; than liking garlic a lot.

I'll take these in order.

1. Friends marrying each other 'just for the hell of it' is already legal.
2. Churches have the right to change the definition of marriage that has stood for millennia since it was their definition in the first place. The state has no right telling God who's allowed to marry.
3. Denying rights to some people based on sexual orientation strikes me as arbitrary (and unjustified), just like denying rights to people who like garlic a lot.

It occurs to me that people who like garlic a lot might have trouble finding partners anyway. Then they'd marry each other. Is that a same-taste marriage?