Is this incest?
Is it incest to date my in-law?
Is it incest to date my adopted sister?
Is it incest to date my adopted brother?
Is it incest to date my stepbrother?
Is it incest to date my stepsister?
Is it incest to date my uncle?
Is it incest to date my aunt?
Is it incest to date my cousin?
Is it incest to kiss my brother?
Is it incest to kiss my sister?
It it incest if my sibling and I have masturbated in front of each other?
The subtext is usually, “Is it wrong?”
First of all, regardless of laws, I see nothing wrong with any kind of physical affection, contact, or companionship between any consenting adults or minors who are close in age, as long as existing vows to others are not being violated. This includes dating, literally sleeping together, seeing each other nude, hand-holding, hugging, kissing (of any sort,) contact with genitals, intercourse, living together, marrying, etc. If these people are right for each other and want this with each other, then it shouldn’t be anyone else’s place to object.
As I always point out, I’m writing about consensual experimentation, exploration, affection, making out, sex, love, dating, partnering, living together, and marriage. I’m not talking about assault, molestation, abuse, or coercion. If someone forces themselves on you, that is wrong regardless of their relation to you.
What is incest? That depends on who you ask. The current definition at Wikipedia is…
sexual intercourse between close relatives that is usually illegal in the jurisdiction where it takes place and/or is conventionally considered a taboo. The term may apply to sexual activities between: individuals of close "blood relationship"; members of the same household; step relatives related by adoption or marriage; and members of the same clan or lineage.
As the Wikipedia entry notes, some people or laws include sex between relatives by marriage, or related by affinity rather than blood (consanguinity,) as incest. Contrary to popular misconception, actual sexual contact between close genetic relatives is not a crime everywhere. There are places where it is legal. Not all places that do have laws against consensual incest define incest the same way. For example, some places have laws that criminalize consensual sex between step-relations, while others don’t.
There are three basic kinds of relations that are commonly called incestuous…
Genetic… if people who are genetically related because they share at least one genetic parent or grandparent, it can be labeled as incest in the literal sense. Someone who shares one genetic grandparent is a half-cousin. Someone who shares two genetic grandparents is a full first cousin.
Legal… if people are legally related through adoption or share an adoptive parent, or have parents who are married to each other (such as stepsiblings), or even if one person is or has been a stepparent to the other, it can be considered incest even though there is no genetic relation.
Social… even if there is no legal or genetic connection, some people might call it “incestuous” if the lovers spent a lot of time around each other, perhaps in the same home, while one or both was growing up. And example of this would be if a woman dated her aunt’s ex-husband, who had been her uncle through marriage for part of her childhood.
So, something can be considered "incestuous" from a genetic, legal, or sociological perspective.
Some places include relationships where there is no genetic connection in their anti-incest laws. Also, there are many places where marriage between first cousins is legal (including some US states) and even common, but other places where such marriages are still denied. There are some US states where consensual incest between full siblings is not illegal, but all states still deny this as a freedom to marry.
Some people think of it as incest if two siblings from one family partner with two siblings from another family, even if both relationships are monogamous and do not swap. Children from the two relationships are “double cousins.”
Genetic relatives brought together into a sexual relationship through Genetic Sexual Attraction or without having grown up with each other, or without one having raised the other, may not have the sociological foundation that would make their relationship socially incestuous, but it may still be considered incest in the legal and genetic sense. This is why many people brought together through GSA do not see their relationship as incestuous, but others, including law enforcement, might.
Whether someone considers a relationship between stepsiblings incestuous might depend on what age they met or whether or not they lived together as children.
Rather than asking if their relationship is incestuous, there are two more relevant questions for someone to ask…
1. Is this illegal? Consensual relationships shouldn’t be illegal, but in some places, some are. This will usually have an impact on how the relationship is conducted and how the information about the relationship is shared. Lovers need to consider what precautions to take, and their family and friends also need to be savvy about the situation. Which takes me to the second question…
2. Will you accept us or reject us? This is more personal. Will this relationship be respected by those around us, or do we need to surround ourselves with people who truly love and respect us?
Lovers should not have to be concerned with the prejudices of outsiders, whether those prejudices are enshrined in law or not. If people are happy together, that’s all that should matter. How do they treat each other? Proximity, bonding, trust, love, privacy, mutual attraction, common backgrounds, and shared interests and outlooks on life can form the basis for a strong, happy, lasting spousal relationship or a mutually satisfying fling, or something somewhere between. Whether lovers share a custodial guardian or genetic parent, met through someone else’s marriage or relationship, or simply met one day while on a nice walk, what matters is what works for them. Is it incest? It shouldn’t matter.