Metamour
The partner of your own partner in a polyamorous or non-monogamous relationship, not your direct romantic partner but connected through your mutual partner.
A metamour is the partner of one's own partner in a non-monogamous relationship structure, such as polyamory. This individual is not your direct romantic partner but shares a connection with you through your mutual partner. Metamours may have varying relationships with each other, ranging from close friendships to polite acquaintances, and the term helps clarify complex family dynamics in plural relationships.
What this means in real life
In a polyamorous triad, if Alex dates both Jordan and Casey, then Jordan and Casey are metamours to each other—they share Alex but aren't dating one another.
What it isn’t
This is not a synonym for 'rival' or 'threat.' Metamours aren't automatically in competition; many develop genuine friendships or cordial coexistence. The term is neutral about the relationship quality between them.
Commonly misused online
Social media often treats 'metamour' as interchangeable with 'affair partner' or 'the other woman/man,' conflating consensual polyamory with infidelity. The term specifically assumes all parties know about and consent to the arrangement.
Based on 3 reference sources, including NIH material. Last verified July 12, 2026.