[cylon]

One thing that is often overlooked is that physical attraction is vital. Once that wears off (and biologically, it's designed to wear off), the relationship is pretty much on the way out. Once that fire goes out, it's like a brother and sister relationship. Then the loins start stirring to move on. Married adults with children who lose the fire are expected to just abandon the hopes of being excited sexually ever again, or to go to counseling and try to trick each other into believing that they are still hot for each other. (The only thing I know of that is supposed to counter this is non-orgasmic lovemaking. Through that, the chemicals that are designed to make us want to leave our partners don't kick in and we stay emotionally bonded for a longer period.)

When the couple are physically still in lust, they can accommodate just about any personal idiosyncrasy or weird habit the other has, because they are awash in that cocktail of hormones and chemicals. Once those chemicals wear off, those weird habits become larger than life and unbearable. People who are horny for each other, stay together until that goes away. That's an essential element and it's almost taboo to mention it.

Because in this society we're expected to think that wanting to be physically and sexually interested in our mates after a certain period of time is selfish or childish or what have you. We're expected to sublimate those desires to the greater good, to the institution of monogamy itself, as if there were such a an entity that existed outside of people's minds.