I have found one of the hardest part of forgiving someone who has cheated on you is the real desire to revenge in some way. especially when you have taken the decision to forgive them.
The almost animal desire to get your own back or do a counter affair just to feel whole.
In my case it was an EA sex texting OM on and off for the first few months of our relationship.
They whole heartedly apologise, they reveal all, they open their worlds, phone, FB the lot. but if you've been there you will know what I am feeling.
I have asked her to do some charity work on the weekends for a charity of my choice. I intend it not to be easy work 
Can others share what they have done or share any tips in overcoming the random rushes of 'revenge' attacks.