Should I Leave My Cheating Wife, Or Have An Affair Of My Own

My wife has cheated on me during a tough time for us. We got back together 2 months ago, but I found out she is still in touch with him. Should I leave her, or have an affair of my own? We have a 5 year old son - this is why I'm not able to consider leaving her easily.

Thanks to all of you who have not jumped on the 'having my own affair' part. I only added this as an option because, her having an affair completely shattered my confidence as a man and is affecting my personal and professional life. I have considered an affair as a way to prove to myself that I can still have a partner if we separate. But now I realize how silly that is. I'm going to try talking it out with her again and resolve this like a man, and hope that will restore confidence in myself.