~G.K. Chesterton: The Innocence of Father Brown.
"A perpetual crisis"
“THE WISE old fairy tales never were so silly as to say that the prince and the princess lived peacefully ever afterwards. The fairy tales said that the prince and the princess lived happily, and so they did. They lived happily, although it is very likely that from time to time they threw the furniture at each other. Most marriages, I think, are happy marriages; but there is no such thing as a contented marriage. The whole pleasure of marriage is that it is a perpetual crisis.”