You've married your sibling, now what?

[muse]

In this hypothetical scenario, you were switched at birth and raised by a wonderful loving family, and no one knows that an accidental switch happened. 23 years later you meet and fall in love with a wonderful person and a few years later you get married and decide to have kids. Which is when the fun starts. Because your parents had a genetic issue of some sort, you and your lovely spouse decide to get some tests done just in case to make sure everything is good. And that's when you find out you're biological siblings. Oh yes, and you've already doinked. Many times.

What do you do now?

[Tribble]

This has happened to people before IIRC. Can't remember what they did once they found out.

[Elheru Aran]

Welp.

--OH FUCK NO; separate/divorce because you've gotten the worst cooties of all.

--Meh. Maaaaaaaybe we just don't ever mention this again?

--What does the law say? One imagines though that if it's been a long enough time period the statue of limitations may expire and they'll shrug and say 'you work it out yourselves'.

Honestly that about covers it. Sure there's a range between the various reactions, but those are pretty much the extremes. Whatever happens, there's going to be a coping period, though, because this is the kind of thing that can break a marriage.

[Zixinus]

The prime question is whether this is a person I genuinely, absolutely want to spend the rest of my life with and whether I believe I can see that happen. And whether both of us are bothered about this revelation enough.

The other question: say we are crazy enough with each other that we stay. Kids? Because if we do, we sure as hell not going through a circuitous route to prevent inbreeding and bad genes.

[U.P. Cinnabar]

I run away. Far, far away.

Failing that, I check myself into the nearest loony bin.

[TheFeniX]

This happened to a gaming buddy of mine.

It did not end well.

[SpottedKitty]

This has happened to people before IIRC. Can't remember what they did once they found out.

Fairly recently, too — I'm sure the last one I remember reading about was only a few years ago.

[Korto]

So who knows?
Move somewhere where they don't know us if necessary.
Then take the decision to never think about it again.

[Iroscato]

Probably have the nastiest, hottest boink of my life that night, then carry on as normal. No kids of course, but since I'd have gone the last few years at Maximum Lannister anyway, may as well stay in gear.

[The Romulan Republic]

So, the general consensus here is "I'd totally pull a Lannister?"

[Broomstick]

I'm afraid I don't understand that reference. Is it a Game of Thrones thing?

[Lord Revan]

I'm afraid I don't understand that reference. Is it a Game of Thrones thing?

Spoiler

The main 2 members of the house of Lannister are twins who have been fucking each (to the point that all royal children are bastards sired by the queen's Brother) and it's the cause of the main conflict the series

[aerius]

To paraphrase one of my teachers, "in our modern times where we have effective contraception, there's nothing wrong with incest since you're not gonna get pregnant anyway". I can't say I disagree, as long as my sister doesn't have a problem with it it's business as usual. All we gotta do is make sure that no one else ever finds out and we're good to go.

[Broomstick]

There are issues with power relationships in incest relationships which is why, even aside from contraception, parent-child incest remains a serious problem. In the case of siblings raised apart who entered into a relationship unaware of being related, though, such power disparities are not likely to be an issue.

[The Romulan Republic]

I'm afraid I don't understand that reference. Is it a Game of Thrones thing?

Since Lord Revan forgot that spoiler boxes don't work in conjunction with quotes (a mistake I've made myself)-

Yes, its a Game of Thrones reference. On the show, two of the main antagonists are Jaime and Cersei Lannister, a pair of incestuous twins who's affair (and succession issues involving their children) are the main impetuous behind about half of the warfare and death in the series.

[Elheru Aran]

In addition to the Lannisters though Jaime and Cersei are probably the best known examples, the Targaryen dynasty is notorious for kings marrying sisters, Pharaonic style. This had obvious effects down the line; insanity was a common curse among the Targaryens. In this particular topic though, that's (hopefully) not an issue with modern contraception.

[The Romulan Republic]

There are issues with power relationships in incest relationships which is why, even aside from contraception, parent-child incest remains a serious problem. In the case of siblings raised apart who entered into a relationship unaware of being related, though, such power disparities are not likely to be an issue.

You know...

On a gut level, my response, trained into me by both society and, I suspect/hope, the natural inclinations of most humans, tends towards "Its sick and wrong". But as long as there are no children (I suppose contraception can fail, but its relatively unlikely), and no clear power disparity or violation of consent, I have a hard time finding a logical argument to justify that position. Personal dislike is not a justification for legislating how people behave in consensual relationships, nor are tradition or religious arguments. The moral arguments against non-consensual/abusive sexual behaviour (including beastiality and child molestation) which justify criminalizing it are hard to apply to all cases of incest.

So while I probably wouldn't campaign for the right to fuck your sibling, I'd have a hard time justifying campaigning against it, too, without abandoning other moral and legal principles that I consider more fundamental to our society.

Same deal with polygamy, actually. There are a lot of cases where it is abusive, and should be outlawed. But I'll be damned if I can come up with an air-tight argument for why it is inherently so.

[Elheru Aran]

To be quite frank, if you weren't raised *with* your sibling, are unaware that they are a blood relation, and have no reason to think otherwise... why would it be, as long as you don't find out, different from any other romantic relationship? First generation sibling incest is usually unlikely to have negative results when it comes to children, so they might not even find out that way, unless they had blood tests before having children and not everybody does that. If you DO find out, and you're already well along in a relationship... and said relationship was going along just fine... why would you nip it in the bud, other than the personal taste thing?

As for polygamy: one argument, I suppose, is financial. If a person cannot support more than one spouse, should they take another, assuming the spouses are not working outside the home (quite common in polygamous societies)? IIRC in fact this was incorporated into Islamic rules for polygamy; if you couldn't support your spouses, you couldn't marry more.

[The Romulan Republic]

The notion of "supporting" ones' spouse financially as a prerequisite for marriage is itself an anachronism, from the days when men were expected to be the provider while the women stayed home. Nowadays, its quite common for both partners to be employed, though others choose to follow a different model.

Edit: It is, granted, an anachronism still common in societies that practice polygamy, like conservative Islam or fundamentalist Mormonism. But it is not necessary for or inherent to a polygamous relationship- indeed, I think it quite clear the such relationships would function more healthily in the absence of "traditional" gender roles.

[Elheru Aran]

Certainly if all partners are employed then support is no longer an issue, granted.

I suspect it's more likely that polyamory becomes more common than actual polygamous marriages. Being in a relationship with multiple people is somewhat easier if you're not legally intertangled with any of them. Polygamy also adds the extra complication of paternity rights and children. If a woman is legally married to two men, and has children... then divorces one of them... does he get paternity rights to all of those children, even if some of them aren't his, by being legally married to their mother? Multiply the number of spouses and it just gets wilder.

[The Romulan Republic]

That's probably the only real argument I can come up with against the legality of polygamy- that it would play hell with divorce and paternity law.

But "It would be complicated" seems a poor justification from prohibiting people from choosing to consensually marry/have sexual relations in a way that is not objectively harmful, but simply unconventional.

[Terralthra]

Complicating this issue is that there's an anecdotally documented effect where close genetic relatives (e.g. siblings) find themselves overwhelmingly attracted to one another on meeting as adults. It's called genetic sexual attraction, and appears to be largely defused by a psychological effect called the Westermarck effect, which desensitizes children raised together to later sexual attraction. While GSA is (obviously) highly variable and not well-studied, the Westermarck effect has been studied, and appears to have at least some basis.

[Raw Shark]

Purely anecdotal, of course, and I've probably mentioned it before, but there is a non-zero chance that one of my exes is my twin sister. We're both adopted, we were born into the system in the same week in the same county of the same state, we are quite similar in personality (including mental illnesses), and we have the exact same unusual birthmark. We couldn't keep our hands off each other, and got horizontal about six hours after we met. I'm about 90% sure that I have fucked my sister a few thousand times.

[Simon_Jester]

I hesitate to ask, and fully understand if you decline to answer... but... how much of this did you learn prior to the breakup, versus during the breakup, versus after the breakup?

O_o

[Alyrium Denryle]

Complicating this issue is that there's an anecdotally documented effect where close genetic relatives (e.g. siblings) find themselves overwhelmingly attracted to one another on meeting as adults. It's called genetic sexual attraction, and appears to be largely defused by a psychological effect called the Westermarck effect, which desensitizes children raised together to later sexual attraction. While GSA is (obviously) highly variable and not well-studied, the Westermarck effect has been studied, and appears to have at least some basis.

At least part of it is olfactory. We have immune system markers exuded in our sweat that we use for mate selection--more important for women (and some gay men) than straight men. It basically works on similar-to-self/not-similar-to-self discrimination. Thing is, similar-to-self is determined by who you are raised around, not your own markers, so in theory the Westermark Effect is at least partially mediated by olfaction.