Do I tell my fwb’s wife with a newborn her husband is cheating?

So I know I may get some hate for this but just to be clear I DID NOT KNOW HE WAS WITH HIS WIFE WHEN I MET HIM. for reference, I am a 26yo female and the man in question is 33. We met online in March 2021 and started seeing each other in person in early April. I am in a happy and committed open relationship with someone, and the person in question (who I will call Max from now on) and my partner have known about each other from the start. They have spoken directly as well. I think this is an important point because it has shaped how I’ve chosen to handle things by a fair degree. When I met Max, he told me that he was married but had been separated from his wife for 3 years (again, given my relationship status and what I wanted I didn’t see a problem with this). In hindsight this was a big mistake. Max and I have a ton in common and got along very well right from the beginning. There was instant chemistry and he did a fantastic job of making me feel safe and seen right from the start which is a huge thing for me because I have an abuse history. We also have a lot in common. We met 7 or 8 times in person (which was a mix of romantic and platonic encounters) over the next couple of months and it became pretty clear to me I was falling in love with him. My partner and I talked about it, and I told Max vis a letter how I felt in late June. I also told him I didn’t expect a return of feelings, I just wanted him to know. I didn’t want it to change anything. He was very gracious about it and thanked me for telling him. He also told me he was getting back together with his wife as a trial run and she was moving back in with him at the beginning of July. I knew they were still friends so it wasn’t a huge surprise to me. He said that he had been inspired by my relationship and they were going to try and make a similar open relationship work. I didn’t see him for a few weeks after that (we were both busy) and then I stayed the night with him on a little trip away. We talked about everything, and we discussed him telling his wife about me. At that point he said they were still figuring everything out but his wife had stated she very much wanted a don’t ask don’t tell situation and he hadn’t told her about me yet. He wasn’t sure what to do and I could tell he felt guilty about that, so we agreed no more sex until he had had that conversation. The next few months were very hectic and stressful for us both and though we stayed friends and spoke often I didn’t see him in person. He has a very high stress job and a few other personal things to think about (including renovating the house) so I didn’t think about it too much. He is also a very avoidant person at times and was definitely struggling a little bit with depression so I didn’t want to put any pressure on him. I didn’t really like that his wife still didn’t know, but again, since we hadn’t seen each other it didn’t feel like the biggest deal. We had simply become close friends and he was my safe person to go to on hard days. Then on November 26th everything changed. He sent me a note in the evening saying his wife had just given birth to his first child. I had no idea she was pregnant. I had no idea they were together and happy when I met him. It was a planned IVF pregnancy. He had lied about everything. I was obviously extremely shocked and upset when I found this out and immediately figured out a way to contact his wife (up until then I hadn’t because I wanted to be respectful of their relationship). I wrote a letter and was extremely close to sending it but decided to call him first and hear his side of the story. He confessed he had been trying to figure out a way to tell me for months about this but had been too scared to. He told me he had been super depressed to the point of self harm over this. He was able to prove to me that his wife and him had talked about an open relationship of sorts but not one like what him and I had (basically she told him he could sleep with other people when he was away working). I was still extremely hurt but given the timing with everything the thought of telling his wife what her husband was doing behind her back (her entire pregnancy) right after the birth seemed like the absolute cruelest thing I could do to a women. I fully told him that if he doesn’t tell her I will, and I still mean that- I’m reaching that point now. She specifically told him not to do anything with anyone that would involve any romantic attachment which we have, which means he is cheating on her in her view. I don’t want to ruin their life. I know max will hate me if I do this, and his wife will too. He has insinuated he will be tempted to hurt himself in some way if she leaves him and I don’t want that on my conscience but another part of me strongly strongly feels like this all has to end and she has a right to know. She didn’t consent to this and if our places were reversed I would want to know. I don’t know much about her but I do know that he is a good husband to her and a good father. I know she loves him dearly and trusts him implicitly even if he doesn’t deserve it. I don’t want to be the reason that all ends. I know a lot of the choices I’ve made have led to this situation and I’m not innocent here. I never wanted this and I don’t want to hurt anyone. Does anyone have any advice?

You don't know any of the stuff you think you do. (Well, Max and his wife probably be angry.) You don't know what she told him. You don't know if he'll hurt himself. You don't know that he's a good husband (he's cheating on his wife)... Or a good father. (Spending time with another woman instead of his newborn, or giving his wife a break is not being a good father) You know what he has told you, which may or may not be truthful. I know, (and so do most of the people reading this) that your goal in contacting his wife is to separate him from her so he can spend more time with you. If you think this is all tawdry and wrong, YOU have the right to stop seeing him. Since, as far as you know, he's been lying since the beginning, you could. But that's not what you're going to do, is it? If MAX is the man who makes you feel safe and seen, if MAX is the one you go to when you've had a hard day, you're looking for an upgrade from your current partner. ​What part of bragging to his wife that you've been banging him qualifies as 'don't ask, don't tell?' No, no, please don't insult people with "she deserves to know the truth." I've known people who've had those arrangements. The other partners calling the spouse isn't part of the arrangement. Calling her to rub her face in his indiscretion is calculated to embarrass and hurt her. YOU have an open relationship. SHE has not agreed to one, so what you would like is irrelevant. Assuming don't ask don't tell is the agreement, if done discreetly, for some people this isn't a deal-breaker. Other people calling the spouse isn't discreet. I know a woman who was very saddened by her divorce. She had an idea there was someone else, (at least for sex) but she wanted to stay married. OTHER PEOPLE nagging her and telling her she 'shouldn't put up with that' bullied her into a divorce she didn't really want. She felt like she had to go through with it, to save face.

Thank you for your input. It is helpful to have an outside opinion. The title is a bit of an attention grab in this, I don’t really think telling her is the best choice currently but it has crossed my mind so many times it’s hard to know what’s right and what’s wrong in this situation anymore. I don’t want this to be an ‘in hindsight’ thing more then it already is. I know I should leave. I did for awhile. He’s asked that I don’t, and I empathize with him enough to agree to stay for now and try to figure this out. I know that’s selfish on both our parts. He has always said she should know. That idea never came from me. I know it’s not my job to police their relationship, but we both agree she should have a say. I will leave if she doesn’t approve. (The most likely outcome). This is the best compromise we have come up with.

"He’s asked that I don’t, and I empathize with him enough to agree to stay for now and try to figure this out." What a load of bs. What that really means is, "I like him better than my partner, but he's not a sure thing." If he's lying 'about' you, he can be lying to you, as well. This is between him and his wife. If he wants to man up he can tell her, or call it quits. Stop painting yourself as this warm, compassionate person by staying with him. You have parity in your moral code (which is to say, kind of low) He's cheating, you're enabling it knowing (at lest you think you do) that his wife doesn't know. Honey, if you were a shining star of morality, you'd have made sure he's available for an auxiliary relationship in the first place. You're twisting yourself into a pretzel painting yourself as an innocent victim. You want this guy for yourself, you want her out of the picture. If his wife finds out (which you CLEARLY, FERVENTLY hope,) she'll leave and you can have him. She won't be good with it, she'll walk, or tell him to. That's really what you want. For someone in an open relationship, it's clear you care far more about your relationship with this man than your other partner. If it was just about having an open relationship, you would just move on from a liar. At least be honest with yourself. You want this guy, and you don't give a d-nm about his wife. If she finds out, you get him.

Most of what you’ve said is probably correct though I disagree on a few small things. Thank you for your advise and wisdom. I will take it to heart. It is time for an ending.