When you do wrong, you expect a consequence. We teach children the consequences of their wrongdoing. It does not make them “bad kids”, but a kid who is learning what is right and what is wrong and the consequences of both.
We do not “punish” (with consequences) a child who has done something wrong in the past and is no longer doing it. That would be judging the child as bad due to past behaviour and taking the perspective that the act of wrongdoing is reflective of their personality until the end of days.
Using the same reasoning for betrayal of a spouse: When the betrayer shows deep remorse and is no longer engaging in any of the behaviours that were related to the betrayal, there need to be no reason to keep on “punishing” the spouse (who has done the work).
How come betrayed feel the urge to punish? The reasons are that they are still hurting, that they are haunted by memories that affect their daily functioning. They feel the urge to show their hurt which is a form of punishment for the betrayer.
Healing: If a betrayed spouse can trust that there is no longer any betrayal in any form, the betrayed spouse will be able to gradually place the wrongdoing in the past and have peace with the fact that consequences have affected the betrayer enough. All anger which equals hurt has been communicated. All communication by this time is a repetition.
To let a former betrayer know that the hurt is still there, a different form of communication (a word, a sign, a symbol) can be chosen to show that the pain is still present. This can be followed by a request. The request can be “I need you to hold me”, I need you to get it”, I need to feel loved”, I need to feel that we are your priority”. The betrayed can communicate the request during a time when there are no painful reminders. It is important that the former betrayer knows what their spouse needs…to have to ask from their spouse what they need when in pain is not helping in particular when they have communicated this. It would be another disappointment.