Most Helpful Guy
It isn't about honesty really. Its about revenge. Making him feel the pain you do. Is that what you want? Truth is its just a temporary fix to help ease your suffering. The pain will still be there afterwards and the fallout of saying it could cause your pain to become worse. There is no going back once it's said and done and could probably ruin any chances of any kind of relationship friends or lovers. Let him play his games. Just act like it doesn't bother you and you are happier without him. This will bother him more.
Most Helpful Girl
Friends don't want their friends to, and I quote, "feel a fraction of the pain he has caused me." I get it. You are hurt, but you are the one that cheated on him during the relationship. If you're broken up, yes, even a day, you're allowed to do what you want b/c you're broken up. You don't get to keep a hold on someone after you've broken up. If you want to come clean because you feel and you know you did him wrong and want to start fresh, that's one thing, but if you're doing it because you want revenge... it doesn't sound like to me you are ready for even a healthy friendship. Plus why would you want to even be friends with someone who as you say, quickly went on to sleep with your own friends?