I am indeed consistent; I would not discriminate (or more precisely I would not have the government discriminate) against any of those choices. As I stated in a previous post, I think marriage should be considered a private religious matter, and the government should butt out altogether.
The aspects of marriage which require government involvement are primarily contractual matters (e.g., property ownership while married or following a divorce). Those could all be handled by standardized or customized contracts between (or among) individuals (irrespective of gender). The government should not be granting special privileges or immunities or tax breaks or tax burdens based upon marital status.