The rumbustious ogre has a hitherto undescribed, but quite imaginable, gap-toothed, beetle-browed ogress of a wife.

Why he married her has never been told.

Why the mortal male whom we meet for the first time at a dinner party has married the amazing mortal female sitting somewhere on the other side of the table is an insoluble mystery, and if we can't tell even why men mate, what can we expect to know about ogres?
At all events, as far as the humdrum of matrimony is concerned, the fairy tales are truer than real life.

The ogre marries his ogress.

It is like to like.