UPDATE: I [39F] was the other woman nearly four years ago. Should I tell his [37M] wife [30sF] now that he’s the biological father of my child?

Original: https://www.reddit.com/r/relationshi...our_years_ago/
First of all I’d like to thank everyone for your comments. I read each and every one of them and there it seemed like the community was pretty divided on my issue, so my wife and I had lots to think about.
A few things: 1) I’m bi and married to a woman. I realized it was ambiguous in the original post though I mentioned it in the comments later. I didn’t think the gender of my current spouse would matter, but a few people were really concerned about my “husbandâ€. I guess generally men would be more opposed to raising a child that isn’t biologically theirs... but in relationship like ours, we know and accept that even in the best possible situation, only one of us will be biologically related to our child. If my wife carries our next baby through sperm donor it won’t be related to me either.
2) I have to admit I did get somewhat worried about the possibility of Mark retaliating legally by suing us for custody if I told his wife about the affair. But the chances of this happening are very slim as we live in a state where parental rights can’t be reinstated once terminated and his time to appeal has long passed. Plus we truly did everything by the book — he was given ample time to appear in court after being served, he acknowledged receipt of the papers in a text message, etc. I know nothing is truly certain but I really don’t wanna live in fear over the very slim possibility of him successfully suing for his parental rights, considering our case is quite standard as far as custody/adoption cases go.
Having said that my wife was still not comfortable with me directly contacting Mark’s wife. She didn’t want me to bear the brunt of Mark’s anger and risk him retaliating on our family in some way. That’s why we agreed to compromise by emailing her anonymously. My wife wrote most of the message from the point of view of a concerned third party. She told her my first name and included general details about our affair that a friend might know, but nothing to implicate me directly. She encouraged Mark’s wife to ask him about my daughter but emphasized that she was being cared for by two parents. My wife’s email was far less emotional and convoluted than the message I would’ve written, which is probably better... we gave enough information so that she can ask Mark about it and/or pursue her own investigation if he refuses to confess. It’s been a few days and so far she hasn’t responded. I am not holding my breath for a response but at least now she knows and it’s not gonna be surprise years down the line when/if my daughter seeks out her biological father.
tldr: my wife wrote an anonymous message to Mark’s wife as a concerned third party. We told her about the affair and the child that resulted from it.
Edit: just to be clear, we gave Mark’s wife enough details about ourselves (mine and my daughter’s first names, how I met Mark through my job at the time, our city of residence, etc) and told her that we can provide more information if she wants. It wasn’t just “FYI your husband fathered a child with a mystery woman, okay, bye!†The email was sent anonymously but I am fully prepared to face her; we just decided that me directly telling her was not the best move. The way I saw it, the truth was gonna come out eventually as I have no intention of denying my daughter her right to seek out her biological dad. I read another post on here where the woman was blindsided after finding out her partner had fathered a child a decade ago. So it was either tell her now or tell her at some unspecified date years in the future. That was how I weighed my choices. ‘Do nothing and just never tell her’ was not an option considering we live in the same city and it is extremely likely my daughter may wish to seek Mark out, if only to get some answers.
Edit 2: I broke off the affair when I found out they were not separated. At the time I was pretty messed up emotionally and was able to rationalize not telling her but I definitely agree that I should have informed her sooner.
Also, yes they are still together and I’m almost sure she doesn’t know because during the adoption process Mark insisted on communicating with us solely through his work phone, he even received the legal documents at work. That was early 2017 so he could’ve told her since, but I doubt it.


Source.

If there's a child involved then yes the wife needs to know.