Traditionally, illicit relation with a married woman has been considered immoral. But there are lot of examples that show such relations have existed throughout history. Some experts believe that this evil has come from Arabs. Usually, uncontrolled sexual urge in married woman is the main driving force for such illicit relations. There are however instances when considerate people deserted such women who had even occupied their beds. In Mahabharat, during his stay in heaven, Arjun rejected the sex-driven plea of Urvashi because he knew that she was the mother of Chandravansha. As such, Urvashi was like a great-great grandmother of Arjun. So, he turned down her pleas for the sake of chastity. Thus, Kamasutra forbids such illicit relations with women who are akin to mother, sister or daughter even by distant relation. Otherwise, Kamasutra has no objection over having a physical relation with a married woman provided that it is the woman who takes the initiative.
All the men and women in a society appear more or less similar. One cannot figure out those men or women who might have extra-marital affairs or are prone to have such affairs. An acute observation of the behaviour, such people can easily be recognized. Experts opine that from figure and bodily postures, promiscuous women can easily be recognized. Old ladies look for these symptoms to ascertain the character of their would-be daughter-in-law. First of all, feet of the woman are observed. If the finger adjoining the thumb is longer than the thumb, if the middle finger is longer than the first finger and the little finger does not touch the ground while walking, such a woman might have a loose character.
Maharshi Vatsyayan says that almost every woman aspires a beautiful male and feels drawn to him at first sight. The nature of males is more or less similar. They too aspire pretty women and like to have their company. Most of the women however manage to contain their desires but a few, of loose character, see no evil in having a casual but intimate relation with handsome males. Another category of women show no interest at first. But with continuous and persisting efforts and pursuing, they too submit their selves to the handsome males. It is an inherent nature of males that they long for the things, which are difficult to get. They like the wife of others more than their own.
But whether one has an access to other married women or not, one should avoid having illicit extra-marital relations. He should be long-sighted enough to foresee the consequences of such an extra-marital relation. More than often, a married woman is deserted by her husband because she has some serious illness or is insane. Such a woman would inevitably seek the company of other males. But the consequences of such relations are always disastrous.

There is a whole range of women who submit before the sexual advances of men without slightest resistance. One doesn't have to work hard to get such women to his bed. This category of women includes those who always stand on the entrance of their home, those who always stand on the roof and look down into the lane, those who enjoy long talks with their young neighbours, those who look intently into the eyes of the men and look sideways when caught, those who hate their husband or hated by their husband, independent spinsters, those who stay with their parents, those who lost their children immediately after birth and those who talk a lot. Apart from these women, women of the gypsies, widows, poor women fond of pomp and show, women who have many brothers-in-law are some other types who are prone to develop extra-marital affairs easily. Those women whose husbands are impotent, afflicted with serious disease, cowards, hunchback, dwarf, ugly, and old also submit easily to the sexual advances of other men.
In the society, there is a complete horde of men who keep on lurking around married women. Some men have addiction like weakness for married women. It is therefore, the duty of every sensible man to guard his wife against these prowling ‘nymphomaniacs'.
Ways to protect the wife: Appoint such member of the family who is fully trustworthy and whose sexual urges have been successfully tested to keep a watch on the wife. Test the character of wife through some trustworthy old lady who has no self-interest.
Reasons for wife running amok: Getting permission from the husband for independent behaviour, living in pressure, talking freely with other men are some reasons that provoke a woman to seek company of other men, despite living with husband. Alternatively, if the husband has migrated out, a woman feels unsatisfied regarding her physical requirements. In such situations, a lonely woman is more prone to fall in the company of characterless women who open many channels for her. Consumption of inebriating drinks and eatables, company of bad men, wandering aimlessly, sleeping at wrong hours and living in someone else's home are some other reasons that encourage a married woman to develop extra-marital affairs.
Elaborating the causes and outcome of extra-marital affairs, Acharya Vatsyayan says that with thorough knowledge of Kamasutra, a man can protect his wife from the leers of other men. Extra-marital affairs always lead to destruction of religion and wealth. Therefore, one should never apply any of the methods described so far to win a married woman in his life. But he should know the subtleties related to these affairs and accordingly protect his wife.