The definition
A metamour is your partner's partner — someone you're connected to through a shared relationship with another person, but with whom you have no direct romantic or sexual involvement yourself.
If you're in a relationship with Alex, and Alex is also in a relationship with Sam, then Sam is your metamour. You and Sam are connected through Alex — you're part of the same relational network — but your relationship with Sam exists on its own terms, whatever those turn out to be.
What the relationship looks like
Metamour relationships vary enormously. At one end: genuine friendship, warmth, the kind of closeness you'd have with a good friend. At the other: two people who know the other exists and maintain polite distance by mutual preference. Most metamour relationships land somewhere between these poles.
What's appropriate depends partly on the style of polyamory being practised. In kitchen table polyamory, cultivating a real relationship with metamours is valued — you'd ideally all be comfortable enough to share a meal. In parallel polyamory, the preference is for compartmentalisation: partners know each other exist but don't actively socialise.
Neither is more correct. The right level of engagement depends on what the people involved actually want, not on what polyamory is supposed to look like.
Why it matters
The metamour relationship is one of the places where polyamory gets complicated in ways that monogamous relationship frameworks don't prepare you for. You haven't chosen this person. They came with your partner. And yet they're present in your life in a way that has real implications — for your partner's time and attention, for the emotional dynamics of your relationship, potentially for shared social situations.
How you feel about a metamour, and how that relationship is navigated, often determines a lot about how comfortable and functional a polyamorous network is. Metamour tension is one of the most common sources of friction in poly relationships — not because metamours are difficult, but because the relationship requires deliberate thought in a way that other relationships don't.
Navigating metamour relationships
A few things that tend to help:
- Meet at some point, if both parties are open to it. An abstract metamour — someone you know exists but have never encountered — is easier for anxiety to work on than an actual person. Meeting in a low-stakes context (a group event, a brief introduction) often reduces rather than increases difficulty.
- Don't expect automatic friendship. You don't have to like each other. You do need to be able to respect each other and function in a shared network without creating problems for your shared partner. Warmth is a bonus, not a requirement.
- Communicate with your shared partner, not through them. Using your partner as a messenger between you and your metamour — or as a buffer for every difficulty — puts them in an impossible position. Where it's appropriate, direct communication is cleaner.
- Your metamour is not your competition. The love your partner has for their other partners does not diminish what they have with you. This is one of the foundational propositions of polyamory, and it remains true even when jealousy makes it hard to feel.
The word itself
"Metamour" entered CNM vocabulary as a way to name a relationship that previously had no name. English doesn't have a word for your spouse's other spouse, your partner's girlfriend, your boyfriend's boyfriend — the people you're connected to through love, at one remove.
Having a word for it matters because it acknowledges that the relationship exists and is worth thinking about. In a monogamous context, your partner's other significant relationships are either non-existent or hidden. In a polyamorous context, they're real, present, and part of your life. Naming the relationship is a first step toward navigating it intentionally.
Related: Kitchen Table Polyamory · What Is Compersion? · Metamour — glossary