One of the oldest, most common fantasies β a threesome β is increasingly accessible as a mainstream relationship option as ethical nonmonogamy and polyamory go more mainstream. Whether you and your partner have been longtime practitioners of nonmonogamy, or whether you’re mostly monogamous but looking for an exciting “hall pass,” you may be interested in exploring what it looks like to add a third person to your relationship, whether for a night or for a lifetime. Where do you start, and how do you know you’re doing it right? Here’s what I recommend keeping in mind.
What kind of relationship are you looking for?

Even once you’ve taken the major step of deciding you’re interested in bringing a third person into your relationship, there are still a lot more details to figure out. There are many relationship configurations under the umbrella of polyamory or ethical nonmonogamy that include a third person β which one(s) are you interested in?
If you’re interested primarily in the sexual novelty of adding a third person, you may be looking for a “unicorn” β someone who’s interested in the thrill of being the new, exciting addition to an existing couple’s dynamic in a threesome. This could be a one-time thing, or something you’re interested in doing regularly β a regular hookup on speed dial for both of you.
Alternatively, you could be looking for a more serious romantic relationship that isn’t just about sex β a girlfriend for both of you. In this situation, there’s also plenty to think about: are you looking for someone that you both date and have largely independent relationships with, even if you sometimes all spend time together, or a full triad (or throuple) where all three of you are in one shared relationship? Are the people in this relationship also free to date other people β is it a fully open or nonmonogamous relationship β or are the three of you only dating each other?
Although you don’t have to have all the answers β after all, part of dating is figuring it out together β it’s good to have a general idea of what you’re looking for so that people you date know what they’re getting into and whether it’s a good fit for them. It’s also key to communicate about this within your primary relationship so you know you’re both on the same page and looking for the same thing before anything gets going.
Check your “couples privilege”

If you’re dating as a couple and looking for a third, sooner or later someone will ask you about couples privilege, and they’ll be right to do so. In the context of polyamory and ethical non-monogamy, “couples privilege” refers to the ways in which primary partners, or the original couple, enjoy advantages and security that newer or secondary partners, like your third, may not have.
This makes sense if you think about it β much like entering a friend group as a new person when everyone else has known each other since childhood, you and your current partner likely have a long history and know each other extraordinarily well; you have a lot of information and established trust, and if the chips are down, you’re likely to choose each other (or band together) with each other rather than the newer, third person. This creates a power dynamic (and insecurity) that it’s important to be aware of.
There are logistical layers to couples privilege as well β a primary partner may have more say in decision-making, for example, have more time or resources devoted to them, and will likely have a greater sense of security and stability in the relationship compared to non-primary partners. If your current partner has major surgery on the same day that your new partner has a sudden family emergency, whose side will you go to? Primary partners may also be given more social recognition or validation, which can make non-primary partners feel less valued or less visible. If you have a big work holiday party, or a family reunion, would you feel comfortable bringing your third β or admitting they exist? Would you introduce them to your parents? Being kept a secret can cause feelings of shame and cause discord in your relationship.
Additionally, couples privilege can manifest in rules or agreements that prioritize the needs and desires of the primary couple over the autonomy and agency of non-primary partners. For example, a primary couple may require their non-primary partners to adhere to certain boundaries or limitations or prioritize the needs of the original relationship over the needs of the triad. Again, think about joining a new group of friends β they may not mean to exclude you, but it’s easy to do out of habit.Β
It isn’t necessarily expected or realistic that you treat your third exactly the same way you treat each other, especially not at the beginning of a relationship. But it’s important for those in polyamorous or non-monogamous relationships to recognize and address couples privilege, and listen to your third about the ways it’s impacting them.
Be intentional about your desires and what you bring to the table

If you’re opening your relationship to a third person, you’ve likely already talked about it amongst yourselves ad nauseum β your hopes, your fears, your fantasies, etc. Keep in mind that any new person the two of you date hasn’t been part of those conversations, and is also arguably in the most precarious position as the newest and most disposable person in the relationship.Β
Although your intentions may absolutely be good and you may be well informed, educated, and intentioned about nonmonogamy, remember that no one you date has any way of knowing that right off the bat; be prepared to take some time to build trust and rapport. Remember also that at least as much as you’re auditioning potential new partners, they’re auditioning you β you’re called upon to make a case for why someone’s life would be better for having you as a couple in it, not just the other way around.
Be willing to adjust your expectations

It’s been said that the only constant is change, and also that you can’t know what you don’t know. You’re thoughtful and conscientious, and it’s likely that you and your partner have done a lot of personal work and growth around opening your relationship, managing expectations and jealousy, etc β unfortunately, no amount of forethought or preparation can account for everything.
The only thing you can know for sure about the journey of adding a third to your relationship is that there will be parts you didn’t expect and couldn’t plan for β more important than planning, then, is flexibility. Be open to things changing or going in a different direction; be ready to make space for your own or your partner’s desires changing, or managing a new development that challenges you. For instance, you may feel warmly and positively toward the new person you’re dating β but realize that your partner has fully fallen head over heels for them. It’s possible that you and your partner feel little to no jealousy between the two of you at all β but the new third person you’re dating has another partner, and you find yourself feeling wildly jealous of them.Β
Adding a third person to your relationship can be exciting and rewarding, but it can also be challenging and complex. Be prepared to face conflicts and challenges along the way, and be willing to work together with your partner(s) to overcome them. Remember that communication and mutual respect are key to resolving conflicts in a healthy and productive way.