In my relationship work, this question is probably the one I hear most often. It is not an easy question to answer. The usual glib answer; "because they can", is really not good enough. People, particularly women, want to know the reason why men cheat, or more particularly, why their man cheated.

Different women have a different view as to what constitutes 'cheating'. For some women, for the man simply to look at another woman may be regarded as cheating, for other women it is being intimate with another person that constitutes 'cheating, and there are some women who appear able to accept flirting and even intimacy with another person but it is an emotional involvement that constitutes 'cheating'.

So let us try first to establish what is 'cheating' and what might be considered 'normal' behaviour in a man. First of all, there needs to be some degree of commitment and exclusivity between the two partners, furthermore, this commitment needs to be understood and agreed by both people. Without this there can be little question of 'cheating' on behalf of either party.

Obviously, marriage, engagement, living together would constitute a degree of commitment. Regularly dating for a period, may also be seen as constituting a commitment. It is here that the confusion starts to arise for a man may not feel he is committed to another person until he has said so to her, for the woman the simple fact that he dates her regularly may be seen as a sign of commitment.

It is where there is a disagreement as to the level of commitment involved, that most problems occur. The man may feel he is free to see another person without it being considered 'cheating' but the woman (his first partner) would be more likely to consider it cheating.

Also, there is a degree to which a man separates the physical act of lovemaking from the emotional attachment to another person. A man is able to perform the physical act without becoming emotionally attached to the woman. A man may often cite that a fling or an affair was 'purely physical' and that it does not mean that he is not now physically and emotionally attracted to his first partner. For a man, this is often true and is not simply an excuse. However, the woman is likely to view the situation differently.

Very often, a woman who suspects her man of cheating wants some evidence or proof of it. This is often to satisfy and corroborate her belief. However, the woman often has not thought through what she would do if the evidence became proof of her man's infidelity.

For the woman, proof of her man's cheating brings emotional hurt and anger. It will often also bring about feelings of distress, loss of self esteem and a feeling that she was to blame. This creates a dilemma for the woman; should she try to repair the relationship out of belief that somehow she has been to blame for his infidelity or should she end the relationship acting out of anger or emotional distress?

The emotional consequences of a man's cheating are not usually apparent to the man, certainly not prior to his act of cheating. It is only afterwards that a man may have some feelings of guilt. However, if he is not found out, then these may subside and the man comes to believe that he can get away with the cheating. Even so, if he tries to continue and to get away with his cheating, he still knows that at some point he is likely to be found out. At this point, it can become a contest, how far can he go without being found out?

To some men, having many partners is seen as a symbol of their status. Even when in a committed relationship, they may think they have a need to boost their status, esteem or ego by cheating. The loss of love, affection and support as a result of a simple thrill, does not occur to them until too late.

In their hearts and minds, men know that cheating is wrong, yet often their egos, their physical needs and, quite simply, the temptations overrule their hearts and minds.

So has this article answered the thorny question of why men cheat? Probably not. This is a complex issue and the causes or reasons will vary from instance to instance. No one can tell you unequivocally why your man may have cheated, not even your man himself.

In such circumstances what you, the two of you, have to decide is whether you want to repair the relationship or end it.

Douglas Woods is a qualified life coach, teacher and counsellor. You can read more about his work at http://www.dougwoods.com. He is also a contributor to Singlescene.net a website for single people.