Ok who really does have more fun?
It might be best to think about how much hurt and pain you felt yourself when your wife told you that she had cheated on you. It's obvious that you still love / care about your wife; so would you really want to inflict that same pain on her by cheating on you? If the answer is yes then it possibly might be the right time to seperate as the cheating is affecting you more than you realise.
I hope you come to the right answer whatever it is.