We've heard so many different misunderstandings about
laws as they apply to relationships and sex between consenting adults. Here in the US, it is especially understandable because laws vary from state to state. There are, of course, fifty states, but there are also other jurisdictions such as the District of Columbia, territories, such as Puerto Rico and the U.S. Virgin Islands, and there are also federal laws, military codes, and laws that apply to "Indian reservations" (small areas where indigenous peoples have some level of self-determination).
If you are concerned about the laws where you are or where you're considering moving, it would be a good idea to see if the laws of that location are searchable online and to consult an attorney who specializes in family or criminal law for that jurisdiction. An experienced lawyer can tell you about how often a law is enforced even if it is still in effect, and might be able to point out ways someone could make it less likely they'd ever be prosecuted.
Some states have laws still on the books that have been ruled unconstitutional by the Supreme Court. The only reason to still have those laws is a deranged hope that the Court decision will eventually be reversed.
Unmarried sex or cohabitation, interracial relationships, same-sex relationships, certain sex positions, even using contraception or sex toys have all been illegal in some places in the US. It might seem shocking, but it is true.
As the show "Sister Wives" detailed, Utah had been the last state to enforce a law against
polyfidelity, or at least saying more than one person is your spouse. We're not even talking about insurance coverage or anything like that. Simply
saying that you have more than one spouse has been illegal. It's outrageous, but true.
When it comes to
consanguinamory, confusion ranges from "I thought it was
illegal everywhere for cousins to have sex" to "There are no laws against consenting adults having sex, no matter how closely related." Both statements are false.
The fact is,
first cousins are incarcerated for having sex in a handful of US states. But about half of US states will allow first cousins to legally marry (and the list of states isn't what stereotypes would have you believe), although some of them have some restrictions. That leaves many states where where they can have sex, live together, raise children together, but can't legally marry. Outrageous, but true.
As far as relatives closer than that, in general, 47 states have laws against relatives closer than first cousins having sex. Ohio allows siblings to be together. Rhode Island and New Jersey have no laws against adults being together, no matter how closely related. Some other states apparently haven't criminalized sex between adults and their uncles or aunts (outside of old, overturned laws that criminalized unmarried sex, given that these people weren't allowed to marry.)
None of the states will knowingly allow relatives closer than first cousins to legally marry, with certain exceptions in certain states for uncles and nieces, for example, mostly a nod to traditions from foreign cultures. Traditions are not respected, however, when it comes to having more than one legal spouse.
Note that these criminalization laws and laws denying marriage rights tend to apply to genetic ("blood") relatives
even if they were legally adopted to different families and never met until well into adulthood.
Some states may have relied on criminalization of homosexuality (which was overturned) and thus might not have anti-incest laws that technically criminalize same-sex consanguinmory. Laws can get very specific, outlawing certain sex acts but not others between certain people. Yes, as silly as it sounds, some specific sex acts that don't harm anyone have been illegal in some places.
The patchwork of unjust laws needs to be changed. There shouldn't be anywhere in the US (or any other country for that matter) where consenting adults are denied their basic rights to have a mutual relationship that includes whatever form of sex they want to have, living together, and, if they want,
marriage, or any other union or partnership offered under law. Nobody should fall in love and then
worry that if they move for a job they won't be able to marry in their new state or might even be criminals.
There's
no good reason to deny these rights. In the US, it should be obvious that
legal precedents have determined that such discrimination is unjust and unconstitutional. But people are understandably confused as many unjust laws are still enforced.