Usually, the married man is seeking for something he fails to receive at home, or he is unhappy with a certain thing his partner is, or is not, doing. They then go out to search for it somewhere else. This may be of a sexual, physical or emotional nature.
The man usually does not want to leave the security he finds in having a family, or he genuinely loves his family and then keeps the mistress on the side to fulfill the needs he is not getting at home.
