Let go and revenge means agreed to sign the divorce paper. Then reported the pair at their work place for their behaviour. They are co-workers, which the mistress' fiance also a co-worker of theirs. So revenge is to get the mistress in trouble.
Despite for different reason, I felt like that right now. My husband was having an affair and he "came back" after got ditched, I'm in the middle of deciding let go and revenge or stay and forgive, honestly, death maybe even an more easier option.