system
Given the following post, respond as if you're commenting on Reddit:
human
CMV: Any Relationship Between Any Set of Consenting Adults Ought to Be Legal

**Breakdown:**

* **Any relationship:** I mean any form of relationship, whether that be polygamy, incestuous thrupples, polycules, plural marriages, interfaith swinging, or any other configuration you can think of.

* **Any Set of Adults:** I mean that everyone that is party to the relationship is an adult^[1] at the time they become party to the relationship.

* **Consenting Adults:** I mean that every person that is party to the relationship gives their informed consent and maintains their informed consent for the duration that they are party to the relationship.

* **Ought to Be Legal:** I mean that for any relationship that meets the aforementioned conditions, there should be no law prohibiting dating, marrying, cohabitating, fucking, and so forth. Further, that any relationship that meets the aforementioned conditions should be treated with legal equality to any other relationship to the extent that is possible.^[2]

[1] *Adult or of the relevant legal age for any pertinent activities.*

[2] *Understandably, there will be relationship structures that are too complex to accommodate in a standardized way and should be navigated case by case to achieve the spirit of the idea of legal equality.*

**Why do I want my view changed?:**

As I am tired and can think of no solid arguments against this, I feel that I must be missing something.

Please change my view. :)

Edit: Due to the opacity and inherent power imbalance, I feel that it is reasonable to say a relationship between parent/guardian and child will be highly unlikely to ever meet the demand for informed consent.
gpt
Nations define marriage for the purpose of establishing parental responsibility and inheritance rules. US law arises from English common law. Dual marriage is an ancient common-law right that has existed “since the memory of man runneth not to the contrary.” Plural marriage has never had that status in English common law, so it can be regulated by the states (which have responsibility for handling marriage as a legal relationship).

The factual answer is that many people consider it immoral, so it’s outlawed for that reason. And polygamy is often used as a way of abusing young women, semi-forcibly marrying large numbers of them off to men.

From a purely pragmatic standpoint, it complicates inheritance rules considerably, and nobody wants to try to untangle that knot. It would be a nightmare for everyone. And it brings no benefits, since polygamists are an almost insignificant percentage of the population.