Mounts that is, not as spouses.
Aww, don't tease me like that!

EDIT: All joking aside... cliff racer mounts?

Only problem with making dragons mountable is the fact that they are self aware...... they are capable of speech and appear to be extremely intelligent...
So are the ones in the Pern series. But then that's a special case.
So are the ones in Warcraft. But dragon-riding in that universe is also a special case, or a number of special cases depending on how you look at it.