I've known my fiancé for 3 years..we got engaged after a year of us being in a serious relationship..we have been engaged for a year and have a 1 year old son. (Who was planned might I add). So our son was born 3 months early and the night before his arrival I had called my fiancé like 5 times. When I never received a call back, I panicked and called his boss who said he was home. (They had a gps on all the work vehicles). He finally called me back and said he was sleeping but when I looked at the phone records there was number to a girl who lived in our area. I dismissed it..afterall his boss said he was home which would make sense that he was sleeping and the number could have been a customer who he needed to contact. Fast forward 6 months and my sister is talking about how teal is such a pretty color and my fiancé says he knows a girl he went to school with by that name..it was the girl whose number I had found that night. Not to cause drama while spending time with family I again pushed it out of my mind but said I wanted to talk later on. That never happened. Now, 1 year later, we're having communication issues and just dumb arguments that shouldn't be a big deal. Him and I tried to talk but came to the conclusion that maybe it's not going to work out so we "broke up" although he stayed living with me. I knew something was up so I did my investigating and messaged that girl and asked if anything had happened. She said not when we were together but little did she know we actually were together. So I played it like she had told me everything which got him to finally fess up after A YEAR of not telling me. We've never had anything this bad happen with us. The last 3 years have not been easy with our families not supporting us and having our son prematurely but we always stuck together. Sure we have the occasion fight that we needed space to cool off but that's it. I don't know what to do. When I agreed to marry him that meant never giving up even when times are tough. For us to agreed to always work things out. Everyone is obviously telling me to leave but I don't think this is something that we should let completely destroy everything we have right now. Him and I still live together and are just trying to figure out the best options for both of us. I've looked into counseling and he's agreed to go with me if that's what it takes to make this work. I don't want to make any irrational decisions based on anger. So basically what would you do? If you've been cheated on, how did you handle It? Did you leave/stay? And if you stayed, did things work out?

Please refrain from being disrespectful. I get enough of that from my friends and family and would appreciate just honesty and life experiences from other who have gone through this. Married or not. Thank you in advance.