Incest, Defined

[blozo]

I personally draw the line at first cousin, although I understand that in some cultures first cousins routinely marry.
Aunts and uncles? Definitely incest in my stories.
Aunt by marriage? I wrote one of those and placed it in the incest catagory, mostly because it was part of a series that started with the MC doing his mom's sister.
Your aunt by marriage is not incest, especially if your uncle is an ass.

Just my opinion.

 

[CuteSlaveLisa]

...if your uncle is an ass...

You can't post that story at all...

Love and Kisses

Lisa Ann

 

[Bramblethorn]

Albert Einstein, Rudy Gulliani, Charles Darwin, Edgar Allen Poe, H.G. Wells, and Jerry Lee Lewis all married and had children with their cousins. So did Franklin Delano Roosevelt.

Not true for Einstein, Giuliani, or Poe. They did indeed marry cousins (Poe first cousin, Giuliani second cousin, Einstein first cousin on the maternal side and second cousin on the paternal) but those marriages produced no children.

FDR and Eleanor were fifth cousins once removed, which is very remote. Technically every marriage is a cousin marriage if you go back far enough, but that kind of marriage isn't what people usually mean when they talk about cousins marrying. Even Guiliani's (second cousin) probably only became significant because it offered a very tenuous excuse to bypass the Catholic prohibition on divorce.

(Catholicism doesn't permit divorce, but it does allow for annulment, i.e. a ruling that the marriage was never valid in the first place. The conditions are vague enough that a good canon lawyer can always come up with an acceptable pretext for annulment if the bishop is on-side.)

At least in Judaism and Christianity Incest is NOT scripturally prohibited.

Say what?

The Bible has several passages, derived from the Torah, which spell out various kinds of prohibited relationship corresponding to what we'd call incest. See in particular Leviticus 18: 6-18, Leviticus 20: 11-12 & 17-21, and Deuteronomy 27: 20-23. "Cursed be he that lieth with his sister, the daughter of his father, or the daughter of his mother."

I don't understand why you keep posting stuff like this that is just obviously not true. It means that people can't rely on anything you say here.

Look at the founders of the twelve tribes. Their father Joseph [assuming you meant Joseph's father Jacob here? - BT] was the grandchild of Abraham and Sarah's brother-sister union. Jacob had eight sons with his two wives whose grandfather was also Abraham and Sarah's son. He had four sons with another pair of sisters. Four women who were certainly his 'wives' in modern parlance.

There are a couple of such stories in Genesis, with people marrying their sisters - obviously if everybody is descended from Adam and Eve, sibling marriages are unavoidable in the early years.

Note that these stories pre-date Leviticus and Deuteronomy, so the prohibitions against incest hadn't yet been laid down. Things that were permitted in Abraham's day may not be permitted to later generations.

 

[Hypoxia]

Last time I looked, I think the risk of serious genetic disease in the children of first-cousin marriages was something like 10%.

I addressed this in What Is Incest[?:

Fucking your clone or identical twin will not have much effect unless one of you undergoes some serious XY-chromosomal tinkering. Mating with parents, children, or siblings DOES likely have serious birth defect risks -- but good hard data is lacking. Figure a risk between about 10% to 30% above the general population. For first cousins the risk is in the range of 1.5-3%.​

Note that caveat: ...above the general population. In much of the world (including Alabama) poverty, malnutrition, environmental risks, and other external factors are more damaging than slight inbreeding.

For somebody who's a known carrier of Hemophilia A, that risk is 25% regardless of who they marry. If we ban cousins from marrying on eugenic grounds alone, then what do we do about the hemophilia carriers? There's a reason "eugenics" evokes uncomfortable connotations.

Ban hemophiliacs from sex unless neutered. Then queers. Then religious and ethnic minorities. Then dissenters. Then you. That's how it works.

 

[SimonDoom]

All this discussion about science, medicine, the Bible, and personal author preferences is completely beside the point.

For Literotica purposes, a story belongs in "Incest/Taboo" if that's the best place for readers to find the story. Period. That's it. The rest is irrelevant.

If a story concerns sex between two cousins, and that's the most salient kink regarding the story, then it obviously belongs in Incest/Taboo, because that's where readers are most likely to find it. Many incest readers won't care to read a story about cousins, but some will, and you can be sure that those that do will look first to the incest category. They're not going to go to fetish or erotic couplings.

 

[TriadWriter]

The following is how the online dictionary defines incest:

in·cest
[ˈinˌsest]

NOUN
sexual relations between people classed as being too closely related to marry each other.
sexual intercourse with a parent, child, sibling, or grandchild.

As you can see, there is no mention of cousins, no mention of aunts and uncles engaging in sex with nieces and nephews, and certainly nothing to suggest that sex between step-children and step-parents are part of the equation.

That's all fine and good, but you have to remember, Incest as defined by a dictionary, isn't the same as Incest as defined under Law.
For example, in some areas, incest under law counts immediate family, and first cousins, but not second cousins. Other areas includes second cousins, or may disregard cousins completely.
Step-relations have never, to my knowledge, been valid considerations.

If you're looking for hard definitions in terms of what constitutes incest, you've already found it on a dictionary level. For a law-level definition, you need to check your local laws.

 

[ElectricBlue]

For first cousins the risk is in the range of 1.5-3%.[/b][/indent]
Note that caveat: ...above the general population. In much of the world (including Alabama) poverty, malnutrition, environmental risks, and other external factors are more damaging than slight inbreeding.

Unless you're a Hapsburg, which I believe is the most commonly cited example of royal in-breeding over many generations. A recognisable look and by all accounts, not the brightest lineage in European history.

And I can assure you, when some of the larger in-bred families wandered into town where I grew up, back in the seventies, it was pretty bloody obvious that it's not the best idea. That was after, I dunno, maybe three generations (following the rapid economic decline of a gold-mining town nearby, where the poorer folk couldn't move away).

Apologists and practitioners can justify it all they want, but there's a solid biological and evolutionary reason every culture in the world holds incest to be a taboo.

Gee, a taboo found in every clustering of human beings over thousands of years, that must be wrong? FFS.

3% ain't noise or a low error rate, it's a significant factor. Elections get won and lost on 3%, just saying.

But Simon's right - the literary popularity is what it is for the simple reason, it's a taboo, and a strong one (for all the non-literary reasons given). Hair-splitting the difference between siblings and cousins is all bullshit really - it's breaking the taboo, is the thing.

 

[Hypoxia]

If a story concerns sex between two cousins, and that's the most salient kink regarding the story, then it obviously belongs in Incest/Taboo, because that's where readers are most likely to find it. Many incest readers won't care to read a story about cousins, but some will, and you can be sure that those that do will look first to the incest category. They're not going to go to fetish or erotic couplings.

Laurel is inconstant (or overworked). I've a tale where bro and sis *almost* make it while fucking new step-siblings, and that slotted into Group, which is fairly accepting of minor deviations. (The sequel was definitely Incest.) Another tale included a cousin but a few of her friends also. It was intended for Group but Laurel sent it to Incest. Usually, with cousins, I'll include siblings etc too, to *ensure* it's Incest.

All this discussion about science, medicine, the Bible, and personal author preferences is completely beside the point.

For Literotica purposes, a story belongs in "Incest/Taboo" if that's the best place for readers to find the story. Period. That's it. The rest is irrelevant.

But really, it's all up to Laurel. If she thinks so then there you go.

 

[TarnishedPenny]

All this discussion about science, medicine, the Bible, and personal author preferences is completely beside the point.

For Literotica purposes, a story belongs in "Incest/Taboo" if that's the best place for readers to find the story. Period. That's it. The rest is irrelevant.

If a story concerns sex between two cousins, and that's the most salient kink regarding the story, then it obviously belongs in Incest/Taboo, because that's where readers are most likely to find it. Many incest readers won't care to read a story about cousins, but some will, and you can be sure that those that do will look first to the incest category. They're not going to go to fetish or erotic couplings.

Bingo.

 

[CuteSlaveLisa]

I did not craft that first sentence well, ALL those mentioned married cousins, MANY had children with those cousins. Het spijt me zeer.

In the old days it was easier, just buy an Indulgence.

Immanuel Kant said that for a work or a theory to be valid it must be internally consistent.

Just as a Constitutional Amendment was required to abolish America's original sin and CHANGE the document. A renouncement of earlier scripture would be necessary to abolish earlier books or parts thereof. So one can logically look at later books as being an addition to rather than a replacement.

And no Jesus didn't renounce the Old Testament, he merely said following it wasn't mandatory. The denomination who ordained one of my lovers says that Baptism and acceptance of the Holy Spirit is all that is NECESSARY, but those who created scripture included Genesis, and I know of nobody who says "don't read it."

Most revivalists believe in the inerrancy of scripture, but far fewer believe in infallibility. I think of it as barely literate kindergarteners using crayons scribbling down a debate between Einstein and Hawking in their 'Big Chief' pads. That's probably generous. Somewhere I have a book listing over 200 contradictions in the original KJV. Some were accidental, others political.

It's not just the exact words, or the translation... Different denominations, sometimes even synods can't agree on precisely what it means. Personally, I own more than the 27 different English language translations of the Bible that I just counted, they are close but not exact.

We can have (hopefully a polite) discussion of what different scriptural verses mean. There are scholars who hold your view, there are also many who hold mine (well technically I hold theirs). We can believe, but neither of us can really KNOW.

Galatians 3.28 is a favorite of mine... "There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ, Jesus."

Now that is from an older (1960s) AKJV. A newer one says bound instead of slave. Others say Gentile instead of Greek, one even says Believer and Non-Believer. Back in 1611, slave was a very real concept. In 1611 and for over two centuries thereafter there were denominations who held slavery to be Ordained by scripture.

When the books that became the New Testament were written Christianity was a sect of Judaism. Constantine co-opted it. Thus Jew and Greek. When the passages you quote were written Hebrews were nomadic tribesmen living in the desert. The head of the clan, the father was king.

Adultery was a property crime, stealing another tribesman's property. So were the so called incest prohibitions, sleeping with your father's wife or daughter was stealing his property.

The so-called prohibition against MALE homosexuality was a prohibition against adopting a common near-eastern practice where warriors took young men as squires and taught them to be warriors in return for sex.

Dietary restrictions were likewise a mechanism of preventing assimilation.

The denomination I belong to has ordained women since it existed and openly gay men for eighty years, obviously they do not see either as contrary to scripture.

There were no jails in the desert. A person was protected by his kinfolk. "His blood on his hands," means to lose protection to be an outcast from kin. God told Cain his brothers blood was on his hands. God could have executed Cain. But Cain was evicted for first-degree murder.

Following Kant if Capital Punishment were the correct sentence, then men would also be executed for shaving, having sex with their menstruating wives, wearing linen and cloth together, drinking water before offering to an ox, eating shellfish or a cheeseburger because scripture uses the same words to prohibit those SINS.

And of course Reductio ad Absurdium it only applies to males, never females.

But THOSE regulations in Deuteronomy and Leviticus ARE IGNORED. (Maybe because Cheeseburger eaters are more numerous than uncloseted male homosexuals?) Most people (especilaly those I perjorativly call "thumpers") don't know what is in scripture.

For instance NOWHERE IN THE BIBLE DOES IT SAY A WOMAN GETS TO CHOOSE who her father tells her to marry.

***

Pentecost Baptist

The evangelist yelled about the lights and the beer,
Said "White you can't save any souls in here.
This place ain't nothin' but a den of sin,
Ain't the kinda' place a Baptist ought to be in."

Preacher said "well we don't really need y'all here.
Ya didn't do a very good job last year.
Only saved one sinner that was Todd McGuier,
The little sum'bich that set the Church on fire."

"Joe's beer joint done been revived,
Only been here an hour and I done saved five.
Sure it's got mirrors and a big dance floor,
But I finally found the flock God called me for."

Here at the First Baptist Bar and Grill,
The only Church in the Bible Belt that smells like a whisky still.
Not a stained glass window anywhere in sight,
Just a bloodstained floor and neon lights,

And the Communion Wine here is always chilled.

We're here every Sunday, we're livin' large,
We're the only Church with a cover charge.
If you don't like our Doctrine and think we ain't Devout.
We'll have our bouncer throw your ass out,

Of the First Baptist Bar and Grill.

-Tim Wilson.

***

And God, she has a sense of humor, just look at us.

Love and Kisses

Lisa Ann

 

[Hypoxia]

And no Jesus didn't renounce the Old Testament, he merely said following it wasn't mandatory.

"Do not think that I have come to abolish the Law or the Prophets; I have not come to abolish them but to fulfill them." One fulfills a contract by following its provisions. I didn't notice divine commands bearing completion or expiration dates. Yeshua bir Miryam said, "Follow the Law" (Torah). Or so uncorroborated myth asserts. He also supposedly told his followers to abandon their families and live in common, and that the rich are damned. But hey, cherry-pick the desired rules! Xians are really Paulists, followers of the torturer and death-squad leader who founded their faith. I distrust torturers -- and those whose god okays infanticide, genocide, and slavery.

Which gets away from incest, even the god-the-motherfucker sort. Religion talk should be over on the GB. OP wanted to stir the incest pot. We presented definitions. But for LIT, incest is whatever Laurel considers it. The End.

 

[KeithD]

Abraham and Sarah were variously depicted as full or half-siblings (same father) in the foundation literature common to Judaism, Christianity, and Islam, so support for incest is as integral in Western religion as you can get. They aren't the only example of approved incest in the foundational documents.

 

[CuteSlaveLisa]

...He also supposedly told his followers to abandon their families and live in common, and that the rich are damned...

Eva and Lillian's father, "The Pastor" in my stories, used to say that Jesus delivered hundreds of sermons on people caring for each other and especially the poor. But there were no recorded sermons preaching the benefits of lower income or corporate taxes or supply-side economics.

...OP wanted to stir the incest pot. We presented definitions. But for LIT, incest is whatever Laurel considers it. The End.

TRUE, however that makes a rather boring thread...

Post #1 "Why is this considered Incest?"
Post #2 "'Cause Laurel says so."

Moshe ben Maimon said "all else is commentary." Yes, but that's the fun part.

Love and Kisses

Lisa Ann

 

[Bramblethorn]

Unless you're a Hapsburg, which I believe is the most commonly cited example of royal in-breeding over many generations. A recognisable look and by all accounts, not the brightest lineage in European history.

And I can assure you, when some of the larger in-bred families wandered into town where I grew up, back in the seventies, it was pretty bloody obvious that it's not the best idea. That was after, I dunno, maybe three generations (following the rapid economic decline of a gold-mining town nearby, where the poorer folk couldn't move away).

I've certainly heard plenty of stories about such families, where inbreeding is accompanied by serious physical and/or mental health problems. But it can be dangerous to assume that the one is largely caused by the other.

Families like that tend to be fucked up in a whole host of other ways which would probably lead to health problems even if incest wasn't part of the story. Under-age mothers, poor maternal nutrition, maternal smoking/drinking/drug use, inadequate or non-existent pre- and post-natal care, violent/abusive family environments... I would bet good money that most of those factors were also present in the families you're talking about. Near a mining town, quite possibly environmental toxins in the mix as well. Without in-depth medical examination it's impossible to be certain of whether young Cletus is messed up because his parents were kin, or because of the fetal alcohol syndrome and all the rest of that crap, or some combination of the two.

Don't get me wrong, inbreeding between close relations certainly is a medical risk. But when incest is part of the story, I think we're too quick to assume that it must be the reason, without considering all the other less-sexy factors that can damage a child.

(I have no personal investment here; incest isn't a kink of mine, and none of my close relatives would be my type anyway.)

 

[Bramblethorn]

Abraham and Sarah were variously depicted as full or half-siblings (same father) in the foundation literature common to Judaism, Christianity, and Islam, so support for incest is as integral in Western religion as you can get. They aren't the only example of approved incest in the foundational documents.

Noting again that the story of Abraham and Sarah occurs several generations before the prohibitions against incest were spelled out in Leviticus and Deuteronomy. It may not have been against the rules in their time; it certainly was after Moses.

For that matter, is it definitely established that Abraham and Sarah share a father? I'm not a Biblical scholar and my Hebrew is non-existent, but my understanding from Genesis 12 and 20 is that Abraham identifies as "sister" for the sake of his own safety:

As he was about to enter Egypt, he said to his wife Sarai, “I know what a beautiful woman you are. When the Egyptians see you, they will say, ‘This is his wife.’ Then they will kill me but will let you live. Say you are my sister, so that I will be treated well for your sake and my life will be spared because of you.”

In Genesis 20, pretty much the same thing happens to Abraham and Sarah again. (What are the odds? Why, it's almost as if somebody has recorded two different variants of the same archetypal story...) This time, Abraham does eventually say that yes, she's his wife and his half-sister through their father. But given that he's already been lying to these people at least by omission, it's not clear to me whether that statement should be accepted as fact. Is there some other source that clarifies this?

 

[Bramblethorn]

We can have (hopefully a polite) discussion of what different scriptural verses mean.

OK then - what do you believe those specific passages in Leviticus about "uncovering the nakedness" of one's relatives meant, if it wasn't a prohibition against incest?

(This is separate from the question of whether those passages are still binding on modern-day Christians; I'm aware of various perspectives on that issue.)

Now that is from an older (1960s) AKJV. A newer one says bound instead of slave. Others say Gentile instead of Greek, one even says Believer and Non-Believer. Back in 1611, slave was a very real concept. In 1611 and for over two centuries thereafter there were denominations who held slavery to be Ordained by scripture.

Fun fact: there used to be a "Slave's Bible" which omitted some pesky passages that might encourage slaves to get ideas about freedom, including much of the story of Moses and the Exodus from Egypt.

Following Kant if Capital Punishment were the correct sentence, then men would also be executed for shaving, having sex with their menstruating wives, wearing linen and cloth together, drinking water before offering to an ox, eating shellfish or a cheeseburger because scripture uses the same words to prohibit those SINS.

Not to mention tattoos. People with Leviticus references tattooed on their shoulders are my favourite kind of idiot.

 

[8letters]

Historically, this is heavily influenced by Mark 10:7-8: "For this reason a man shall leave his father and mother, and the two shall become one flesh; so they are no longer two, but one flesh."

Under that interpretation, when you fuck your father's wife, you are effectively fucking your father - same flesh. This is where we get the "in-law" terminology from: your sister-in-law was, for purposes of marriage, equivalent to your sister, and so on.

I'm not remotely religious, and my views on incest between consenting adults are pretty relaxed. But my father remarried when I was in my thirties, and I can assure you that my stepmother is close family and mentally Off Limits even though we've never lived together.

Personally, I don't think the Bible has anything to do with the society's treatment of incest. There's three things about incest relationships that provoke their disapproval:
1. A lot of incest relationships involve an adult using their authority to initiation the relationship with a child and keep it secret. That's incredibly harmful to the child. Many non-incest authority relationships are illegal (teacher-pupil, doctor/psychiatrist-patient) for the same reason
2. Some incest relationships are incredibly harmful to the extended family. If Homer cheats on Marge with someone he works with, that's a tragedy for Homer, Marge and their kids. If Homer cheats on Marge with Marge's sister, now it's a tragedy for all of Marge's family
3. To me, parents want to control/monitor relationships that can lead to their non-adult kids having sex, particularly daughters. So if a daughter in high school wants to "study" alone with a male classmate, parents are going into high-anxiety mode. But for a family to work, there has to be trust that male and female family members can be left together without sex happening. Mom and Dad need to be able to leave a brother and sister together without worrying they'll fuck like bunnies. That applies to adopted siblings, half-siblings, foster-siblings - you name it. Also, when the extended family gathers, the parents don't want to have to worry about their kids slipping away to have sex with another family member.

So to me, incest is about betraying the trust of the family. The people involved know that the family will disapprove, but they can't stop themselves. If the relationship is so distant that the family doesn't care, then it's not incest.

 

[KeithD]

For that matter, is it definitely established that Abraham and Sarah share a father? I'm not a Biblical scholar and my Hebrew is non-existent, but my understanding from Genesis 12 and 20 is that Abraham identifies as "sister" for the sake of his own safety:

As much as anything in the internally inconsistent Bible is. And if you are literal and go all the way back to the beginning, Eve being basically a rib of Adam is about as incestuous as you can get.

Other examples of accepted incest exist in the Bible:

https://www.quora.com/What-are-the-10-stories-of-incest-in-the-Bible

But on the OP, this isn't even a discussion to need to have on Literotica submission.

 

[R. Richard]

Many of my best selling stores are incest based stories. Apparently a lot of readers like incest based stories.
Each of my stories has a plot, a real plot. Many of my incest bases stories involve brother sister incest or mother son incest. However, there's always a real reason why the incest occurs.
Friday Night is an example of two incest involved groups. The conclusion involves the breakdown of the groups into non incest based relationships.
I have a publisher that specializes in incest based stories. That publisher can get my incest based stories published with some of my other publishers that won't publish the same thing for me???
As to the real world effects of incest, there are remote valleys, in the Appalation Mountains, where everyone is closely related to everyone else. The results include 'blue people.'

 

[CuteSlaveLisa]

OK then - what do you believe those specific passages in Leviticus about "uncovering the nakedness" of one's relatives meant, if it wasn't a prohibition against incest?..

When I lived in St. Louis in the 1980s RABBI S. Howard Schwartz was on faculty at UM-Saint Louis, I took a couple of his classes. His Hebrew is 10 to the 32d better than mine. He said it was best translated as "embarrassment" because the same Hebrew terms were used in non-sexual contexts.

Subordinates do not embarrass their bosses/elders at work/home lest they be fired/asked to leave. Just as the worst your boss can (legally) do is fire you, cast you out, so too that was the prescribed result of violating the two-hundred or so rules in L and D (185 of which are blatantly ignored).

This dovetails nicely with my previous paraphrase of Hypoxia in this thread and my book detailing the internal inconsistencies in the KJV, as well as the very readable commentaries of Dr. Bart Ehrman at UNC Chapel Hill.

Dr. Ehrman calls himself an atheist. To me atheism is just another BELIEF system, we CAN'T KNOW. We are, all of us, eternal wanderers, searchers. The Preacher was a nineteen-year-old Infantryman who liberated Dachau, I am certain that informed his beliefs.

The KJV was commissioned by a Royal practitioner of sibling and cousin incest. A nobleman who wished to deny that route to power to mere commoners.

Fun fact: there used to be a "Slave's Bible" which omitted some pesky passages that might encourage slaves to get ideas about freedom, including much of the story of Moses and the Exodus from Egypt.

As Dr. Ehrman says the Bible has often been intentionally modified for political purposes. (Misquoting Jesus, who changed the Bible and why.)

Not to mention tattoos. People with Leviticus references tattooed on their shoulders are my favourite kind of idiot.

IIRC only slaves are to be tattooed or pierced. My ONE discrete tattoo has the names of my six lovers in intertwined script, and I wear their rings. Because I am theirs (and they are mine).

Love and Kisses

Lisa Ann

 

[Shelly2inme]

What about sister-inlaws?

When I was in my early teens my sister and I used to masturbate each other. Once in a while we still go down on each other. I never viewed it as incense*. But now she fucks my husband from time to time. They are not related by blood so would people still view that as incest?

*(I am glad somebody was paying attention. But I do think that pussy scented incense would be marketable.)

 

[KeithD]

When I was in my early teens my sister and I used to masturbate each other. Once in a while we still go down on each other. I never viewed it as incense. But now she fucks my husband from time to time. They are not related by blood so would people still view that as incest?

I agree that it wasn't "incense." (Sorry, couldn't resist)

 

[CuteSlaveLisa]

When I was in my early teens my sister and I used to masturbate each other. Once in a while we still go down on each other. I never viewed it as incense. But now she fucks my husband from time to time. They are not related by blood so would people still view that as incest?

Oh, I am certain you meant that on your eighteenth birthday you discovered sex and the incredible feel and taste of your sister, nudge, nudge, wink, wink. If you are honest and open it sounds totally cool to moi. If you gift or share with her, hey that is what sisters do, take care of each other.

Its no accident my family is two penile people and five vulva persons. Survival of the species. God made boys to want to broadcast their seed. She made girls to nurture that life, to want one boy to protect her and their offspring. Give and take. The girls accept two instead of one. With spit-roasts as a wondrous side benefit. The boys accept five in place of infinity, but five is doable. Its worked since '78 for us.

Six would work, or eight but the concept is sound.

Love and Kisses

Lisa Ann

 

[CuteSlaveLisa]

I agree that it wasn't "incense." (Sorry, couldn't resist)

I would spank you, but I am thinking you'd enjoy that.

Love and Kisses

Lisa Ann

 

[Hypoxia]

Post #1 "Why is this considered Incest?"
Post #2 "'Cause Laurel says so."

That's the bottom line. End of thread.
_____

Oh wait, we must bloviate. Okay, IRL incest sucks, and LIT Incest rocks because LIT fantasyland is not IRL bummersville. IRL incest is usually abuse and, as mentioned, is the same as non-incest power imbalances: kid abused by authority figures.

Don't bring IRL to LIT except as a morality play, with abusers appropriately punished, or not. Forget all the legal and religious and biological stuff except for flavor. In LIT, close relatives fuck consensually. The consequences won't be bad or the story will get lousy reactions.

LIT Incest is positive. Leave the readers masturbating.