Adopted Siblings Get Married

Sometimes I wonder about strange things, and lately I’ve been wondering about the following hypothetical situation.

Let’s say that I’m adopted. At 20 years old, I meet a wonderful woman who I fall deeply in love with. With so much in common it seems we are made for each other. Not only do we have almost identical likes and dislikes, but we are BOTH adopted. We get married, buy a house, and have a few kids.

Fast forward 20 years and, for whatever reason, we decided to try to find our birth families. We both manage to find our biological mother and discover that our mother is the same person. We are brother and sister!! Our mother had fraternal twins, a boy and a girl, and gave them both up for adoption!

So what happens now? Do we stay married? Are we forced to divorce? Is it possible to be convicted of incest even though we had no idea we were siblings? Would it be morally wrong to stay together? Would it be illegal to stay together? Obviously, this would be a tough situation. What are the legal ramifications? What are the moral ramifications?

Saw this on Private Practice.

The marriage becomes immediately invalid when the incestuous nature becomes apparant.
You are not forced to divorce. You are forced to discontinue recognition of the marriage - it is effetively never valid.

As soon as you realize it’s incest, everything, Morality, Law, etc… is against you.

Back in the 1990s, there was some talk show that had a family in just this situation. They were battling the state because they didn’t want their whole family torn apart, but they were facing an invalidated marriage and, IIRC, they were being threatened with having their kids removed from their home unless they continued to live only as brother and sister rather than husband and wife.

Maybe I can find some reference to it on some site that has info about trashy talk shows.

You’re both adopted, from the same country, have the same birthday and probably look quite similar? One would hope those factors put together would be a red flag, at least to prompt you both to get blood tests before marrying, even if your state doesn’t require you to.

Emotionally, it could tear your family apart and ruin your kids’ lives. Part of this would probably have to do with other people’s reactions, including those of your adopted family, assuming you let them know. It’s hardly the same as marrying a relative you grew up with, or even a non-blood relative like a stepfather. But people are people and incest is pretty taboo, so I imagine they’d judge pretty harshly.

Well, ignore the twins part. A brother and sister (or, even, half-brother and half-sister) could find themselves in this situation without those clues.

You’ve already been married 20 years, and have kids. Legalities aside, I don’t think there’s any ethical obligation to dissolve the marriage. You’re a better match than most couples, and are apparently happy with each other. The kids should get some genetic testing, but other than that, what’s the problem?

If you weren’t twins, your criteria wouldn’t raise any red flags.

  1. You’re both adopted… Neat coincidence!
  2. You’re both from the same country… Of course! Something I share in common with millions of other people.
  3. You look “quite similar”… Define “quite similar”. I’ve got a Scottish heritage, and I look like a lot of other people of similar heritage. Meanwhile a lot of siblings don’t look anymore alike that the Skywalker kids. My dad was a tall skinny auburn-haired guy who looked like Howdy Doody. His brother looked like Lou Costello.

The OP isn’t talking “separated at birth”, just long-lost siblings.

If I found myself in such a position, I would just keep quiet about it. It would obviously be quite a shock, but if you both kept quiet, who would know, especially after 20 years.

After my father and my aunt died, my mother married my uncle. It was illegal under Jewish law (although a reform rabbi did agree to perform the ceremony), but I don’t think it violated any secular law.

Off-topic, I know a pair of step-siblings who married. Their parents were both divorced and her father married his mother. They were both teen-agers when the parents married and they never actually shared a household (until they were married).

Would depend on the jurisdiction. English common law used to consider that within the prohibited degrees of affinity, and barred the marriage. I don’t know if that’s still the case. The origins of this common law prohibition date back to King Henry’s Great Matter, since he argued that his marriage to his brother’s widow was improper. The canon law of the Church of England adopted that principle, which in turn passed into the common law.

That English common law in turn travelled to a lot of Commonwealth countries. That type of marriage was illegal in Canada until about 40 years ago, when Parliament passed Acts allowing such marriages.

If some of the issues with incest are due to potential genetic problems in children, what are people thoughts if the couple are treated so that they can never have children (eg vasectomy)?

I’m sure it’s still legally wrong but what about morally?

What about two gay brothers or two gay sisters? Identical gay twins separated at birth?

It was? I thought the Torah demanded that a man marry his brother’s widow if she was childless?


Deuteronomy 25:5

If brothers are living together and one of them dies without a son, his widow must not marry outside the family. Her husband’s brother shall take her and marry her and fulfill the duty of a brother-in-law to her.

So how does your mother marrying your uncle go from being potentially mandatory to being completely illegal?

Nothing one sees on Private Practice is accurate to any great degree.

I imagine it would void the marriage. I most jurisdictions, there are two types of “you can’t get married.” Void ab initio and voidable. With void ab initio marriages, the state does not recognize them, and doesn’t really consider it has the power to recognize them. With voidable marriages, they’re typically things that, if they were known at the time, the state wouldn’t issue you a license. But if they become known later, the state will sort of grandfather the marriage as OK so long as the spouses want to continue. The classic cases of marriages void ab initio are marriages when at least one party is already legally married to someone else, and sibling marriage.

So you wouldn’t have a legal marriage. Ethically I don’t see a problem with it, although I agree that you should shut up, because there’s nothing the public likes better than sticking its nose into other people’s bedrooms. It would be immoral to have (further) biological children without doing genetic testing to make sure you’re not going to pass on something. I don’t really know if today’s science would give enough information to answer this definitively. However, the Catch-22 is that you couldn’t do such testing without a serious risk of word getting out.

Another issue is the legality of getting spousal tax or employee benefits once you know your marriage is void. I think this would probably be fraud, and would probably be a kind of fraud it would be impossible to guard against. My off the cuff answer would be you should get a nominal divorce so you’re not legally married. You don’t need that to live as a married couple, but it would protect you from getting things through fraudulently holding yourself out as married without having to admit to everyone why your marriage is invalid.

Oh, yeah, I guess you’d be committing incest every time you slept together. Another reason to keep it quiet.


There was (supposedly) a case just like this that came up in the UK a while back, but I remember being suspicious at the time and for all my Googling all I can find are people citing the guy who referenced the case. Now they’d surely want privacy, but it was a bit too vague for my liking (and used as an example of why records should be open or something about in vitro). Anyone know what I’m talking about?

And perhaps I’m deluding myself, but if my husband and I were both adopted and knew anything about it e.g. that we were both adopted from the same state around the same time (versus internationally, and were of the same ethnicity), and both by strangers (versus step-parents or family members), I feel like I could count on myself or a cruel friend joking about incest, having a laugh, then not being able to sleep 'til I’d put it out of my head with a blood test.

This is yet another thing to add to the list: don’t try and find your birth parents.

In local new recently we had a case of a woman looking for her birth mother and was shot dead just for asking.

Persons who give up children for adoption are often at a bad place at the time. Persons attempting to locate birth parents are chasing a media created fad.

I doubt you would. You wouldn’t look at the person and say “That’s my sister”, you’d look at her and say “That’s my wife, Jenny, who I’ve slept with many, many times.” I can’t imagine having a simple factoid like “we have a shared parent that we’ve never met” change your entire view of a person. It just doesn’t seem that in-your-face.

You’d contact V.C. Andrews?