From the Desiring God site of Pastor John Piper:
Except in a sentence like this one, I don’t think we should use the term “gay marriage” or “same-sex marriage.” I think in our everyday discourse, we should say “so-called gay marriage” or “so-called same sex marriage.” I would encourage politicians, pastors, and people to adopt this simple habit. The reason is that in God’s eyes, there simply is no such thing as so-called “gay marriage.” It does not exist. It cannot be made to exist by desires or decisions or language or laws. God ordained marriage with the words: “A man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh” (Genesis 2:24). Marriage is the union of a man and a woman in a lifelong covenant as husband and wife.Going by Piper's logic, Newt Gingrich is on his third "so-called marriage."