Adultery is still the Scarlet A of relationships. It was only an emotional relationship with no sex; it was just sex and no emotional attachment; it was your fault because you didn’t appreciate me; I couldn’t help it, s/he just came on to me. Seriously!!! It’s adultery! You stepped outside of your marriage and the vow you made to be faithful to your spouse (you know those words in the wedding ceremony while you were focusing on the kiss).
The worst thing about adultery is the breaking of the trust between you and your spouse. It’s a betrayal of the worst kind. Some people can work around that hurt and continue on with their marriage and others head to divorce court.
The anger over the betrayal will make you say and do horrible things. You will go through boxes of tissues and bottles of Scotch or wine. You may go back and forth between forgiveness, reconciliation, and hate. The road for each couple is different. Remember the old adage, it takes two. S/he did not steal your spouse without the consent of that spouse. Forgiveness is different from forgetting. Forgiveness can be very difficult and can take years. Forgetting will never happen.
It’s harder when the other person in the affair now marries your Ex. The new step-parent has a relationship with your child and you are in constant emotional turmoil over that reality. Talk to a therapist, not a judge (don’t keep going back to court to salve your hurt). Deal with your anger on your own and don’t drag your child into the battle. The snide remarks made to your children about the step will come back to bite you. You can be respectful of the step and maybe one day you’ll be able to forgive. While you are waiting for that illumination, remember that your child has a relationship with this person and may actually benefit from that relationship.