I would like to get something off my chest that has made me sick to my stomach since the day I found out. I work with this fella that has been messing around with a married lady… that’s on her for putting herself in that situation and not being faithful but it’s on him for continuing with it. She was recently married a couple years ago. You ask me why is this your problem?
Well coming from a marriage with a cheating spouse this kind of hit home for me. Not only did everyone lie to me that knew about my husband, but I literally tore myself apart just to find the god awful truth. If a stranger or someone that was around them when it happened would have came to me and told me, it would of saved me a lot more time and heart break.
So I am asking for advice on if I should contact him about how shitty of a wife he has, or simply keep my mouth shut. I feel bad for her husband and dislike the boy I work with, but I believe I owe it to the cheated on spouses. Please help!
LemonVibe 
I say …tell. I get it. I too was cheated on and if someone would have just told me …
These are questions to ask yourself.
Are you ready for the inevitable blow back on you?
Are you really doing this to “save” someone from cheating or are you doing it for your own personal revenge against your own demons in the past?
Do you know FOR SURE that they are not in a alternative relationship like swingers or polyamourus bf/gf? Do you have real proof of the cheating? If not then you may make some serious enemies while looking like a jerk and all they have to do is say you were trying to get them in trouble, because it’s well known you dislike them at work. They could go to HR on you for causing a poor work environment and suddenly you are the periah at work.
I would ignore this unless it directly effected you. I just watched something very close to this happen at the office. The couple turned out to be poly and he’s now looking for a job. They are not and in their line of work he’s going to have to deal with them again and again in this area, so is unlikely to get back into that field unless he moves away.