Betrayal by a loved one in any relationship can be difficult to face, but thoughts of revenge can be a way to avoid dealing with the reality of the situation. Some people believe they have the right to charge a toll on the person who has done this, but few of them have a clear enough mind to figure out something that will really be worth their time. Some of them might realize that simply leaving the other person will be more than enough revenge, and many partners will seek something they believe will do damage to their former partner.
It might feel sweet to contemplate revenge, but it usually does not work out well for the person who takes the steps necessary to carry it out. Their belief that their actions are justified by their pain seems realistic, but the courts of today will not necessarily agree with them. There are few instances where a judge or jury will look at a person and agree their act of vengeance was within reason.
Leaving aside any legal issues, it can be nothing more than an act of self-pity for a person to claim revenge on a disloyal partner. The person they were with already had a low opinion of them, and it will not get any higher when they act in a childish manner. Their need to continue the relationship in this bizarre fashion could point to one of the reasons the person chose to be with another.
Dreams of revenge can be a good way to help a person feel better, but turning them into acts might not be worthwhile. For those who truly want revenge on a cheating partner, moving forward with their life could be the only good answer they will ever find. Meeting someone new and finding a better relationship with a faithful spouse is what they really need.