Sometimes a person will cheat on their partner because they feel like their partner is not giving them as much attention as they would like them to.
There are many people who will cheat on their partner because they found out their partner was cheating on them. As a way of getting even with their partner they will cheat because they believe it will make them feel better because they are attempting to hurt their partner in the process.
Lack of sex
Many people will cheat if they are not getting enough sex in their relationship. If their partner is unwilling or unable to keep up with them sexually, they will find someone else to fill that void.
Loss of interest
Sometimes a person will lose interest in their partner if their partner has gained some extra weight after they started dating. This person may no longer be physically attracted to their partner so they will find someone else who they are attracted to and they will cheat.
Fulfilling a fantasy
Many people have fantasies about being with a certain type of person it may be someone within a certain age group, race, or body-type. Even though we all have these fantasies many of us will not act on them however, there are some of us who are not strong enough to fight the temptation and will act on these fantasies.
Someone may be content with their partner. However, if they have the opportunity to have sex with someone they fantasize about, they will cheat on their partner in an attempt to fulfill their fantasy.
Some people cheat because they believe they will not get caught
Sometimes a person may be in a great relationship but even though they are happy they will cheat on their partner simply because they believe they will not get caught cheating.
Many of these people will cheat when they know their partner will be away for a certain period of time, and they know exactly when their partner will return. These people believe cheating on their partner is ok because their partner will never find out about it.
There are many different reasons for people's infidelity in a relationship. Although infidelity cannot be justified people who get caught cheating will try to justify their actions.