The argument of “I cheated on him because he cheated on me” is legit crazy. You remember how hurt you were when he cheated? Why are you continuing it now? I don’t understand people. I really don’t.
If you find someone who is willing to love you through all your bullshit and flaws and insecurities and mistakes.. why would you ever jeopardize that for one night of “I’ll show him who’s boss”?