When each person strives to outdo the other in devotion, the marriage is ideal and worthy of envy, for such a union is beautiful.

“In marriage, there must be complete companionship and concern for each other on the part of both husband and wife, in health and in sickness and at all times, because they entered upon the marriage for this reason as well as to produce offspring. When such caring for one another is perfect, and the married couple provides it for one another, and each strives to outdo the other, then this is marriage as it ought to be and deserving of emulation, since it is a noble union. But when one partner looks to his own interests alone and neglects the other's, or (by God) the other is so minded that he lives in the same house, but keeps his mind on what is outside it, and does not wish to pull together with his partner or to cooperate, then inevitably the union is destroyed, and although they live together their common interests fare badly, and either they finally get divorced from one another or they continue on in an existence that is worse than loneliness.”

Musonius Rufus

And, for those who don't know...

Gaius Musonius Rufus was a Roman Stoic philosopher during the reign of Nero. Rufus is considered the Roman Socrates and was the teacher of Epictetus.