My wife and I have an open marriage but one of her partners just moved into our house without my permission. How do I tell her this is not OK?

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• For Love & Money is a column from Business Insider answering your relationship and money questions.
• This week, a reader in an open marriage faces a dilemma: What to do about an unwanted roommate.
• Our columnist taps Janet Hardy, coauthor of "The Ethical Slut," for help navigating this breach.
• Got a question for our columnist? Write to For Love & Money using this Google form.

Dear For Love & Money,

I am the primary breadwinner, and my wife and I have an open marriage. I agreed to this reluctantly, and at first it was fine. We established boundaries and we both started playing the field.

Then she started getting serious with one particular woman. This violated our rules, but we had a long talk about it, and I agreed to it. Soon this woman began coming around a lot, and then a few weeks ago, she came over again. Except this time, she stayed.

She's been here ever since — eating our food, using our utilities, watching our streaming channels, and contributing nothing. I resent the financial aspect of this, but honestly, most of my resentment is due to her presence in my life period.

How do I talk to my wife about this? I agreed to everything up to this point because I love her and don't want to lose her. But I can't afford to financially support another grown adult.

Sincerely,

Bad at Boundaries

Dear Bad at Boundaries,

You say that your wife's lover spent the night and never left. Perhaps this is optimistic of me, but I don't think that necessarily means she's moved in. As long as her prior living situation remains stable and available, I think you can approach this situation in the way it has been presented to you: a really long slumber party.

As a paying resident of your home, you have every right to pull your wife aside and tell her it's time to wrap up this party. Or at least ask her to acknowledge the reality of the situation so that you can put some parameters around it.

That said, I'm not an expert on polyamorous or open relationships, so I discussed your dilemma with Janet Hardy, one of the foremost authorities on the topic. Hardy is a writer, educator, and the coauthor of over a dozen books on sexualities and relationships, including the cultural phenomenon "The Ethical Slut: A Practical Guide to Polyamory, Open Relationships, and Other Freedoms in Sex and Love."

When I read your letter to Hardy, not only did she have wonderful insight to offer, but she's also been in a similar situation. She called her experience in this area "one of the hardest times" in her marriage. So, you're not alone.

Set boundaries around tangible behaviors

Hardy's first observation after hearing your story was that you and your wife made a common beginner's mistake: You agreed not to let potential outside relationships get too serious.

Hardy explained that feelings are difficult things to control, so instead of trying to create rules around intangibles such as feelings, it's important for couples who are planning to open up their relationships to establish ground rules around tangible behaviors instead.

Hardy listed a few examples: Set time periods for the original couple to spend together, specify limits for time spent with outside partners, and reserve some experiences for one another.

Set an appointment to talk things over with your partner

But while you can put boundaries around tangible things going forward, for now, what's done is done. And Hardy was adamant that your situation must be dealt with swiftly.

As Hardy put it, "Two people who don't like one another living under the same roof is an explosive situation." That said, she encouraged you to refrain from addressing the situation during a fight when tensions are running high.

Get ahead of the explosion by setting an appointment to discuss the issue. Initially, you should address the situation with your wife, not her lover. Make sure you both have a chance to speak and really listen to what the other has to say. Talking sticks might sound cheesy, but they work.

But this meeting shouldn't be limited to troubleshooting the issue of your new roommate. Schedule regular check-ins, and, if it turns out that you can accept your wife's new lover as a long-term addition to your life, bring them into these conversations as well. In fact, if this is the case, Hardy suggests you each have individual check-ins with one another.

However, this will depend on what you and your wife decide about her lover moving into your home full-time. If you agree to a family-style poly relationship, treat it like a family. But if you decide you're more comfortable keeping outside intimate relationships compartmentalized, they need to stay compartmentalized. Whichever you and your wife choose, Hardy says it must be built on those tangible goals I mentioned earlier.

In Hardy's case, she was in your wife's position. Her adult child needed help, so, without asking her partner, she let her son move into her and her partner's already cramped space. Her partner was, like you, understandably upset.

To successfully navigate the situation, Hardy's partner told her what he needed from her. Things like "I need a certain amount of time for just us." But such clear parameters require honesty. For you, this will mean getting familiar with the feelings sitting just beneath your resentment.

Because sure, paying for another adult's bills against your will is a justifiable complaint — a complaint you should address by charging your new roomie rent at the very least.

But you admitted that your feelings go beyond money, and it's imperative that you understand these feelings so you can turn them into a list of things you need to feel satisfied within your relationship. Then communicate these needs to your wife.

Perhaps you need more affirmation and attention, or maybe you simply need your wife's lover to go home. This is what Hardy's partner ultimately required, and the solution to her dilemma meant her son getting his own place.

I know you don't want to lose your wife, and I worry that this fear has kept you from being honest with both her and yourself. But having an open relationship doesn't just mean having a polyamorous sex life; it also means being open and honest with your partner.

Rooting for you,

For Love & Money

This story was originally published in October 2022.