Infidelity in marriage is highly harmful to a marriage because two people becomes one flesh which means more than just fleshly affection.
People who commit infidelity do not just confess that they have been unfaithful even When caught, they will still lie and explode in self-righteous anger that they would even be accused.
The level of trust that is required for this act, makes one vulnerable, and this is one reason why sex should be confined to just marital relationship.
To dishonor trust through infidelity is destructive to an individual and to the marriage.
It is the treachery of a confidence, the violation of a vow, the collapse of security, and the destruction of a union.