Polygamy is Outdated, but Sex outside Marriage is Not
Man's Second Nature
Throughout the history of man, there are millions of cases of men having more than one wife. By inference man also shares his emotion of love with more than one woman. Man’s history also records that women in most cases accept their fate and continue loving the man though he may shower his affection on another woman. In contrast, there are very few recorded cases of women loving and marrying more than one man.
The Solitary example
In history, the solitary example is the Princess Draupadi in the Mahabharata who married the 5 Pandava brothers name Yudhistra, Arjuna, Bhima, Nakula, and Shehdeva. These 5 had one father but 2 mothers with the first 3 Yudhistra, Arjuna and Bhima being from one queen and the other 2 from the younger queen. This marriage to the 5 brothers was also not the norm, but a requirement of the mother of the Pandva's who had asked her sons to promise they would share everything together. Probably when the Queen Kunte made her sons promise this she did not visualize marriage, but the sons interpreted this as applicable to marriage as well and when Arjuna won Draupadi in a swayamwara (marriage contest) as per their oath to the mother Arjuna informed Draupadi that he could not marry her alone as they had promised their mother that she would have to marry all of them. The Mahabharata does not record what Draupadi felt, but she did conceive from each of the 5 brothers. This is an exception and not the norm.
The society at large has accepted this facet of a man desiring more than one woman. Islam has codified this in the marriage laws which permit 4 wives and any number of temporary wives or Mutta marriages. It has also simplified divorce, but only for the man so that he can take another woman as wife to remain in the ambit of 4 wives. Women have no say in this matter.
In Hinduism, there is no mention of monogamy. The Laws of Manu are a complex set of rules but they permit a Hindu man to take a second wife. It was only in 1955 when the Hindu Marriage Act was passed by the Indian parliament under the aegis of Jawaharlal Nehru that marriage was restricted to one wife. This act also gave some rights to women and they could also file for divorce.
The Christian religion, in particular, the Catholic faith is the most rigid in this aspect. Divorce is not allowed and the norm of one man and one wife is accepted for many centuries. But this is the ecclesial position as in practice divorce in the west is much easier than in the east and correspondingly men can take other wives. Even in Catholic dominated countries, the incidence of infidelity is very high, much more than in the east and it is not uncommon to love another woman though she may not be your wife.
These are the facts, but there is a physiological aspect to this. Man is a male and an advanced mammal with a highly functional brain. He also does not age and can continue loving a woman till well past his prime. Hence the adage that “Horses and men don’t age” holds true biologically as well. A man by his mental makeup can never be satisfied with one woman all his life. There are cases of lifelong monogamy, but then many hide their true feelings and live alive of ‘morality’. Somehow the deep impact of religion has looked upon sex as something aberrant and correspondingly man is conditioned by this. It was only the Hindu religion that recognized the power of sex and incorporated the Tantra sex which is claimed as a path to salvation.
In everyday life, man has diverse interests, much more than a woman and as such it is in his mental makeup to love women. Most men are capable of loving more than 2 women and also emotionally bonding with them. This is a mental makeup of the women and by nature, as social scientists have noted man is polygamous. Women, on the other hand, are mentally attuned to one man and some can feel g hurt at the intrusion of another woman in their life. However, thousands accept this, as it is a part of their psyche. Man all over the world is the same and it will not be an understatement to state that this is God's way of regulating life and should not be treated as an aberration.