Of course, there are various criticisms with this traditional and conservative definition of marriage and family. We must not overlook that, in fact, many of it may seem logical and intuitive but that – alas - human nature follows its own logic.
Part of it may be the fault of our libido, or sexuality, something that has come into the forefront especially since Freud has made sexuality the focal issue of his psychoanalysis. And no matter how much we may stress that we are essentially good and moral, that sex is lust and leads us into temptation and strays us from the correct path, that sex may be even filthy, that sex is unnatural and even abnormal among same-sex partners and whatever else many people might throw and object towards sexuality, it is a given fact, that it is a relevant and undeniable part of human nature.
And I believe that it is the importance of sexuality that causes families to break up, that marriages seemingly blessed in heaven crumble and fall apart. To say that it is “natural” for humans to be in a lifelong union with the same partner is a lie when it comes to our makeup and biology.
Not that it is impossible, but it is rather difficult and takes continual effort and will, and even discipline. When sex becomes a routine, when all the secrets and hidden territories of one's partner are discovered, sexual life becomes rather dull and not as thrilling as it used to be. That's when many couples try to spice up their sex life with games and toys and other types of practices.
Yet the temptation to look for sexual gratification elsewhere, that is, with other partners is constantly present within the individual; it is a definite possibility always lingering in the back or forefront of the mind.
However, there are other factors that impede us from engaging in such sexual behaviors, and one of the strongest would be our conscience. After such an “illicit” act that would temporarily gratify and still our desires, remorse would gradually manifest itself in the conscientious individual. The remorse is not so much because of the act itself, but of its secrecy, its betrayal, where the culprit must keep on smiling while there is inner guilt and turmoil inside.
What would be a solution to this dilemma? An open relationship. By taking away the guilt element and being completely honest with the other person, sexual gratification with other people loses much of its taboo. It is a mutual agreement, and, as such, both would be able to enjoy their relationship, yet at the same time have the door slightly ajar and have sexual adventures outside of the relationship whenever it becomes necessary or desirable.
Would such a relationship actually work? It should be possible, yet it would depend on a clear mutual agreement. Emotions, however, do not always play their part. Men in evolutionary terms tend to be more jealous of sex than women. Male instinct needs to ensure that if their partner is pregnant, that it is undoubtedly his and not someone else's child.
Women, again in an evolutionary perspective, tend to be more jealous when it comes to emotions since they want to ensure that the husband or the father of their child will not end up leaving them behind; they want somebody who would stick around and be available for their own needs and those of their child or children.
Apart from jealousy, human nature often tends to be possessive. This causes a lot of problems and tensions within any relationship. We would claim that the other person is "ours," meaning that they become our commodity. To be able to share that person with another, particularly sexually, seems counter-intuitive for us, at least in our culture. Some cultures used to “lend” their wives to the guest as a sign of hospitality, but for most of us, it raises our hair on end to even consider such a thing.
Consequently, in theory, an open relationship would be the best option to satisfy one's sexual urges, as a form of catharsis. It would also take away some of the stigma of marriage as a kind of prison one is “committed” to. However, on the other hand, it is a difficult undertaking, as humans are often possessive and jealous, and where a relationship is built on being together, a kind of exclusive twosome without the threat of an intruding third party or onlooker.