Is Cheating ever justified ??

I ask this as we as a society seem to scorn those who are unfaithful in relationship and immediately sympathize with the hurt and vilify the cheating party but is infidelity justified in certain cirstances. My parents met while both married to other people, when the met they felt a deep and undeniable connection and left their other partners. 4 children and 26 years later they are still together and very happy almost like soulmates was their infidelity justified??