Oh Classic Prudie, you never disappoint.

mrsconn23

Over 20 years ago I had an affair with a married woman who became pregnant with my child. She reconciled with her husband and they raised the boy as their own. I have not had any contact with my biological son, at the husband’s request. No one in my family knows I have a secret son. Two weeks ago I found out my niece (my sister’s daughter) is engaged, and the groom to be is none other than my biological son! Prudie, I am livid that my son’s mother and her husband did not stop this relationship in its early stages. “No, Bobby, you can’t date that girl because she’s your biological cousin” is all it would have taken. I contacted the woman and she swore she didn’t know our son was marrying my niece since my niece has a different last name. I asked her what she planned to do to stop the wedding and she said she’s doing nothing! Our son doesn’t know anything, and according to her, cousin marriage is harmless! Prudie, how do I bring this up with my niece and her parents? I have never had any contact with my son, and I don’t think I should approach him about it. He doesn’t know his father is not his biological father. I don’t want my niece to live in incest because of my past mistake. Please help.

short+sassy

I remember this one!

I think the LW should get in touch with the son's parents and say something like, "Look, I was originally going to take this secret to my grave because the last thing I'd want to do is upset your family.  But now he is going to marry his first cousin and, I'm sorry, but this is no longer a secret I can keep.  My niece and your son both need to know the truth, so they can decide what they want to do.  I will give you all the opportunity to tell your son first.  How much time do you need?" 

With, if needed, the ultimatum that he will tell his niece on X date, if they refuse to talk to their son.  

charlotte989875

I actually think you reach out to your sister and your niece and explain the situation. You don’t need to involve your former partner in this at all. Your niece is family, you should tell her. There is no way to prevent your son from finding out the truth and summers that’s going to suck. But they’re not going into this with all the relevant information. 

Casadena

I imagine if they don't tell them it will end up like LW from a few weeks ago (months?  2020 time isn't real) where they found out they were related after having been together for many years and were now super grossed out.  It's going to suck, but it's the right thing to do I think. 

STARMOON44

Eh I’m team cousin marriage is harmless. The increased risks are really minor if you aren’t in a culture of generations of cousin marriage. 

Casadena

STARMOON44 said:

Eh I’m team cousin marriage is harmless. The increased risks are really minor if you aren’t in a culture of generations of cousin marriage. 

SIB I actually agree with you 100% that cousin marriage is whatever.  However, i think most people would at least want to know that they are marrying a cousin.  I think it would be horribly awkward to find out after the fact.  

short+sassy

STARMOON44 said:

Eh I’m team cousin marriage is harmless. The increased risks are really minor if you aren’t in a culture of generations of cousin marriage. 

I totally agree with you on that.  My personal hope is, after the initial shock, the couple wouldn't think it is that big of a deal and proceed with their wedding plans.

But, at the same time, there are a lot of people who...even if it is more an emotional thing...have an opposite view.  So the couple should at least be informed and make their own decision.

MyNameIsNot

I would want to know if I were niece or son. I agree with talking to niece, probably through sister first. While we don't even know if they're planning to have biological children and the risk may not be enormous, it does seem like in a world of cheap DNA genetics testing that it's likely that they're going to find out at some point anyway. I'd want to know young and early, rather than finding out 20 years into a marriage.

MissKittyDanger

I think the biggest issue is that they don't know they're cousins.

It's always a shock, but enh. Whatever when it's cousin's, not for me but whatever. It's not "flowers in the attic"

MissKittyDanger

Side fun story - apparently my mum and dad's family lived close to each other and there was brief question if they were distantly related because of this.

They're not, but my mum's great aunt use to baby sit my nana all the time lol

downtondiva

I think they should be told they are cousins. Let them decide if they are okay with it or not. Better that they be directly told before the wedding than finding out years later through Ancestry.com. 

MesmrEwe

I'm team "Informed Consent"...  No one ever wants to admit infidelity, and the Dad that raised him is his father, just not biologically but niece is still a biological cousin and not that it's likely to happen, there are reasons that they must make an informed decision on (possibly genetic testing because if they are in a family that is a carrier of any genetic conditions, that can be dealbreaker stuff by itself or impact all things family planning.  Niece is an adult, so is her FI, but if the mother has had communication and refuses to approach the subject it's up to him (bio dad) and also even extend the option for genetic testing to confirm that being the case and that he's not making it up or the Mom had multiple partners and wasn't sure..  End of the day, both Niece and her FI deserve to be informed that they are bio cousins even if that means this year for Christmas they get a "23 and Me" kit as a family to do together!

banana468

STARMOON44 said:

Eh I’m team cousin marriage is harmless. The increased risks are really minor if you aren’t in a culture of generations of cousin marriage. 

And if they find out too late they could be in one of the 24 states or numerous countries where it's not legal.