Is Open Marriage Legal in the US? Like, Actually Legal?

Is it illegal to have an open marriage in the US, and what about your wedding vows? 

 

An increasing number of US couples are exploring open relationships and polyamory, both inside and outside of marriage. This can lead many people to wonder not just about the ethics of open relationships, but the legality of them. So, are open marriages legal in the US?

 

Yes, open marriage is legal in the US

 

The simple answer is yes – open marriages are legal in the US. In general, it’s perfectly legal for married partners to consensually date other people, form intimate bonds with other people, and even raise children and commit to other people outside their marriage. 

 

(Whether or not it’s ethical is entirely up to the couple and their beliefs; every adult should have the right to define their marriage in a way that works for them.) 

 

 

What is an open marriage? 

 

Before we get too far along, though, let’s define open marriage! Open marriage is a type of consensual non monogamy or ethical non monogamy, which means that both people willingly agree to be non monogamous. 

 

This act of consent is an important distinction to make here, because consent is what differentiates an open marriage from adultery, and adultery is illegal in some states. (We talk more about adultery in the section below.)

 

The takeaway here is that an open marriage isn’t one-sided, and shouldn’t be confused with having an affair. Couples discuss the idea of 'opening' a marriage before it happens. They decide on any relationship guidelines or boundaries that are important to them and then give their mutual consent to be non monogamous.

 

 

Couples talk about relationship guidelines and boundaries when deciding if an open marriage is the right choice for them. (Photo: Juan P Photo and Video / Pexels)

 

How common is open marriage in the US? 

Reliable open marriage statistics can be difficult to find because of the sensitive nature of sex and non monogamy in marriage. However, Pew Research Center conducted a poll on the topic in fall of 2023, called "Views of divorce and open marriages." They found that nearly 33% of Americans say that open marriages are “acceptable,” with an additional 16% still undecided. Of the age groups interviewed, younger respondents were increasingly in favor of the practice, with a majority 51% of Americans between the ages of 18 and 29 considering open marriages acceptable. 

 

Current statistics: 51% of American between the ages of 18 and 29 consider open marriages acceptable

 

These numbers suggest that open marriage may be becoming more common in the US, or at least that younger people may become more likely to try it in their own relationships.

 

 

What about adultery? Is adultery illegal in the US? 

 

As we mentioned above, adultery is illegal in some states. Currently, 16 states have laws against adultery, with legal punishment ranging from fines to felony convictions.

 

In Wisconsin, for example, adultery is a felony punishable by up to $10,000 in fines or three and a half years imprisonment. In Michigan, the penalty is up to $5,000 in fines and five years imprisonment. In Florida, where adultery is a misdemeanor, the fine is about $500. 

 

Related: How many times can you get married in each state?

 

 

What’s the difference between adultery and open marriage? 

 

To emphasize this point a little more: open marriage and adultery aren’t the same thing. The difference between an open marriage and adultery is consent. In an open marriage, both parties agree to be non monogamous before opening up their marriage. Adultery occurs without the other person’s knowledge or consent. 

 

Since this consent could be challenging to prove during divorce proceedings, couples in an open marriage sometimes choose to put their non monogamous agreement in writing ahead of time, to protect against misunderstandings if their relationship sours. (This isn’t legal advice, just an observation; we recommend you talk to a lawyer if you have any questions about prenuptial agreements or similar documents.)

 

 

What about bigamy? Can you be married to more than one person? 

 

It is not legal to be married to multiple people at one time, however, under any circumstances. That’s called bigamy, and it’s a big no in every state. 

 

The line between an open marriage or poly marriage and a bigamous one is very clear: an open marriage is a consensual decision between two married people to be non monogamous, while bigamy is the act of being illegally married to multiple people at once (with or without their knowledge). 

 

In an open marriage, you're only married to one person. 

 

• Learn more: What You Need to Know About Bigamy

 

 

Polyamorous commitment ceremonies are legal and increasingly common

 

Although open marriage and polyamory aren’t synonymous, these arrangements are both types of ethical non monogamy that can lead to a long term committed relationship with someone outside of your marriage. Because these relationships can be very meaningful, some people choose to celebrate them with a non-legal commitment ceremony – which is completely legal to do. 

 

Commitment ceremonies are symbolic rituals that honor the commitment between two or more people. They are not legally binding, and do not require any legal paperwork or an officiant to perform. And because they don’t mark the start of a new marriage, it’s completely legal for married people to have a symbolic commitment ceremony with someone outside their marriage. 

 

 

People are becoming more comfortable talking about their polyamorous relationships openly, and nearly 51% of Americans between the ages of 18 and 29 are ok with the idea of an open marriage (according to a recent poll by the Pew Research Center). (Photo by cottonbro studio / Pexels)

 

 

What about the whole “forsaking all others” thing? Are there ‘open marriage’ wedding vows? 

 

Some traditional marriage vows include promises to be monogamous, such as “I promise to remain faithfully yours, forsaking all others…” But couples aren't required to make marriage vows promising to be monogamous, or to make any wedding vows at all!  

 

For this reason, couples who want a non monogamous marriage often write their own wedding vows instead of using traditional ones, so that their promises are more authentic and personal.  

 

Open marriage wedding vows can include any wording you choose, and any promises you want them to. For suggestions, check out: 

 

• Sample Vows for Polyamorous Wedding & Commitment Ceremonies

 

 

To sum it up…

 

To sum things up – yes, open marriage is legal in the U.S. Adultery is illegal in some states, and bigamy is illegal everywhere in the country. Open marriages are created by mutual consent between partners, and polyamorous relationships are sometimes celebrated with symbolic commitment ceremonies. 

 

Disclaimer: We’re a church, not lawyers, and this isn’t legal advice. This article is meant to be educational only. State marriage laws change often, and we recommend you contact a family lawyer who specializes in marriage and divorce with any questions you may have about open marriage. 

 

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More Polyamorous Wedding & Ceremony Ideas 

 

• 5 Unity Ceremonies for a Polyamorous Wedding with 3 or More Partners
   
• What happens during a commitment ceremony?
   
• Ejemplos de Votos para Bodas Poliamorosas y Ceremonias de Compromiso
   
• Polyamorous Commitment Ceremony: Advice for Officiants on What to Say, Where to Stand, and More
   

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