My (36m) wife (35f) asked me to keep the paternity of our child a secret. We BOTH cheated.

My wife and I have been married for 10 years. We were together for 5 years before we married. We conceived our first child after several years of trying. We were overjoyed! <br><br>Then the affair happened. It lasted for about 6 months. I know the exact timeline, because that’s what took place between my wife’s conception dates of our child and her affair partner. I tried to forget about the whole thing, but I couldn’t. It continued to eat at me. How could she? How could I? I had no evidence, but I always suspected her affair continued even after his death. I never told anyone the depth of our marriage issues. Not even my family.<br><br>Flash forward. Our child is now 5 years old. I got a strange message asking when my older child was born. I was confused, because at the time I only had a 3 year old. I was sent a photo of her child, with a birth certificate. My son’s middle name, a tattoo of my name in script on her shoulder, and a birthdate 3 months before my wife delivered. I was stunned. <br><br>I confronted my wife and learned that her affair partner had been trying to get in contact with her for most of our marriage, but always got blocked. She tried to get his new number, only to learn that he had passed away. Days after learning of his death, she received contact from a girl claiming to be his daughter. Apparently his mother had been paying for everything, and wanted nothing to do with his mistress or bastard child. <br><br>I told my wife I was leaving, but she begged me to stay. To stay for our son. She told me she had been in contact with the girl for over a year. The girl was 17 at the time and her mom was getting ready to kick her out with nothing. She had been secretly supporting her. I was irate, but she showed me photos of them. The girl was wearing a diamond cross around her neck. I was also in the background of a photo. My son’s middle name was her first. Apparently she had bought everything for her. <br><br>At that point, I’d had enough and told her I needed space. I left for a few nights and eventually returned. When I returned, she’d had a meltdown. Our son was crying, she was crying, the whole thing was a mess. I calmed the situation down, but then she begged me to stay. For our son. She told me she’d do anything if I just stayed. I told her to leave, that she’d made her bed. She begged and begged. Eventually, she told me she was in debt almost $100k. She cried. I gave her an ultimatum. She needed to erase everything and to never mention it again. If she did, I was leaving and would fight for full custody. We agreed to pretend it never happened. <br><br>That was two years ago. In those two years, we’ve slowly regained intimacy, but only in that sense. Emotionally, she may as well be my roommate. I’ve only seen the girl twice. Both times, I pretended I was her uncle and that my wife was her mother. It’s weird and creepy and I can’t help but wonder if the girl knows my wife is her mother. My wife’s lies are so deep and complicated I’m not sure I’ll ever learn the truth. <br><br>The only reason I know about the money is because I got the collection calls. I’d almost forgotten until I got the calls and thought back to that night. She said she’d do anything. I want to leave, but our son is my world. He’s my reason for being. I don’t want him to have a broken home. Does that make me a coward? Does it make me a bad husband? I feel like I’m living a lie. I know I’m the one that suggested it, but sometimes the weight is almost too much to bear. I’m drowning in this lie. Advice?<br><br>TL;DR: My wife cheated. I cheated. I learned she got pregnant by an affair partner. Her partner died. His daughter contacted her. My wife had been in secret contact with his daughter for over a year. His daughter is my biological niece. My wife begged me to stay. I gave her an ultimatum. I regret it. I want to leave. What do I do?<br><br>Edit: I didn’t cheat on my wife because of her cheating. The timeline of our affair is the same. The conception dates are the same. The timeline of our affair is the same. I started my affair about 6 months before I learned of hers. <br><br>Update: I’ve been arguing all day about this. The fact remains, I don’t know the truth. I don’t know if she’s my child. I don’t know if my wife told her the truth. I don’t know anything. I want to know. I want to know if he was right. If I’m raising a child that isn’t mine. At the very least, I want to know the truth.