Researchers have found partnerships characterized by dissatisfaction, unfulfilling sex and high conflict are often at a higher risk for infidelity. People who have a hard time with commitment may also be more likely to cheat in some cases. If there are unmet needs or this like limmering euphoria or falling in love is no longer kind of sustaining your bond, cheating may become more likely. But still you don't have to cheat in these situations if you don't love someone anymore. You can always break up with them or discuss an open relationship instead of betraying your partner's trust in you.