Infidelity Support Group
Any relationship in which one partner engages willfully in sexual relations with another outside of the partnership is considered to have experienced infidelity. This breach of trust is often traumatizing for the faithful partner as well as the relationship, and support is often needed to heal emotionally and to decide whether or not the relationship should continue after...

While it is always 100% the fault of the CS it is true that you do need a cheating partner to commit adultery and many of whom are married as well.
It's sad how women will sleep with married men and steal away husbands just as it is horrible of a man to take another's wife.
It just shows how the general population of the world in every society is broken and not above such destructive and selfish decisions/lifestyles.