I would argue that it isn't special rights, but equal rights.

We're not talking about poly or animals, but a union contract between two adults. In a sense it is saying that your heterosexual marriage is more valid than say James and Daniel of Rutland who have been together likely longer than either of your marriages.

Personally I could never look at Nikulai and state that he can't marry the one he loves. It hurts me to think that others could.