Long ago, before women had equal in the workplace, a man would spend all day at work mainly only with men, then come home to his wife.
Now there are many women who are very young and beautiful and intelligent and sexy throughout the workplace that men interact with every day.
Men and women, humans, are merely an animal and driven by nature which commands animals to make as many babies as they can to propagate the species with a diverse genetic pool.
When there is no temptation, meaning no women to look at as in a monastery, the sexual drive is not activated. This is why the Jews and Muslims separate men and women in prayers, so we can focus on God instead of hooking up. It's just a sad fact of being human. Denial or disagreement does not change reality.
However, when a man is surrounded by attractive, sexy and desirous females all day, it is impossible to not have the animal instincts activated.
Sexual energy is the creative and stimulating energy that makes life interesting and gives a person a spark to live. That is why we all like to have some sexual stimulation in our life. This energy should never be stifled.
The only way to stop this desire is imprisonment, but then more than just sexual desire is removed, the whole spark for life is killed.
Being conscientiously undeveloped, as 98% of humans are, the mind will be driven by the animal nature and reject the concept of not being able to mate with all desirous partners. Since there are so many potentials every day, the idea of monogamy is sub-consciously rejected by the basic animal nature.
Commitment is a reliably new mental concept in terms of human history. All ancient religions and traditions, and some modern ones such as Islam and Mormonism, practice polygamy.
If a man does not understand that the desires are purely animal in nature and not for any value other than to fulfill the basic evolution of the species, he will confuse the desires for other women with not being satisfied with the current partner.
On the other hand, if the woman does not understand what is driving her man to fear commitment, ie the animal nature consistently whispering in his ear, or other organs, that he should not be tied to one woman, her frustration and fear can cause her to be in a way that will encourage him to want to leave and push him away.
Understanding the workings of the human machine is the only way to use mind over nature and make a conscious choice with emotional comfort to remove the power that desires have, rather than let desires control decisions.