Besides normal sexual cravings, there are many unconscious or only partly conscious causes which drive human beings into being faithless to their life mates.
Many women take lovers, many men take mistresses for purely egotistical reasons. Justly or unjustly they feel a certain lack of appreciation in their mates and make up their minds to get even with them.
"Getting Even" is one of the great neurotic cravings, one which has led to numberless offences, including crime and suicide.
To some neurotics with a sense of inferiority, an extramatrimonial affair seems to be the sole means of restoring one's self confidence. "I am of no account at home but to some one else I mean the world."
Many neurotics use "romance" and "inspiration" as convenient scapegoats.
"But for the inspiration I derive from my affair with So and So, I could not do my work properly," and this is true in a good many cases, but in many more cases, any one else would do just as well as a lover or mistress. Some neurotics, who remind one of Madame Bovary, the heroine of Flaubert's great novel, feel that accomplishment and the fullness of life are naturally associated with sexual irregularities.
Too inferior to accomplish anything by dint of hard work, Emma Bovary childishly expected love to accomplish everything for her. Other neurotics, incapable of any creative work, consider romance as an achievement in itself and proceed to call every carnal dissipation romance. Just as inferior boys at the gang age steal or destroy in an absurd attempt at "doing something out of the ordinary."
Some neurotics never feel safe very long with any sexual mate; they grow afraid or suspicious and seek safety in the arms of some other human being in whom they unconsciously hope to find the father or mother image to which they were over-attached. Their search for the safe mate, that is, for the parent image, is, of course, always unsuccessful.