What would you call the husband of a female president?

So Hilary Clinton is now running for President of the U.S. And the first thing I was thinking about was this, what do you call the husband of a female president?

If more women run for the presidency and actually win, would "he" be refered to as the First Man? Just one of those things I ponder. In this case, Bill Clinton will just always be refered to as former President Bill Clinton, or simply President Bill Clinton. But this is an unusual case.

First man? First husband? First Man-bitch? Who knows.