Is there a specific reason? Do they feel guilty? is the woman just hotter?
Most Helpful Guy
People cheat because they are not getting their needs met, and because for some reason they feel unable/unwilling to leave their present relationship.
For some, their 'need' is a variety of sexual partners, in which case they should recognize that monogamy is not for them.
As for why they are unable/unwilling to leave, they may be afraid to be alone, which I don't have much sympathy for ... or maybe they have kids and don't want to be part time parents.1