A more thorough explanation:

Infidelity is when someone is unfaithful to their partner or spouse. This means they break the promise they made to be loyal and honest in their relationship.

For example, if a married person has a romantic relationship with someone else, they are being unfaithful to their spouse. This is also known as adultery.

Another example of infidelity is when someone lies to their partner about where they are or who they are with. This breaks the trust in the relationship and can be just as damaging as physical infidelity.

Infidelity can cause a lot of pain and hurt in a relationship. It is important to be honest and communicate with your partner if you are feeling unhappy or tempted to cheat.