Polyfidelity is a type of consensual non-monogamous relationship structure where all members agree to remain sexually and romantically exclusive to one another, forming a closed group. This contrasts with more open forms of polyamory, where individuals may engage with partners outside their primary relationships.

In a polyfidelity arrangement, the focus is on maintaining commitment and intimacy within the established group, which can range from a triad (three people) to larger networks. Each participant typically knows about and agrees to the relationship dynamics agreed upon by the group, fostering a sense of trust and security.

One of the key features of polyfidelity is its emphasis on the emotional and sexual bonds among the members, often leading to shared experiences, communal living arrangements, or collective decision-making. For instance, a group of four individuals may choose to enter into a polyfidelity agreement where they exclusively date each other, attend social functions together, and support one another in their personal lives, while remaining closed off to relationships with individuals outside the group.

The success of polyfidelity often hinges on effective communication and clear boundaries, as participants navigate their feelings, desires, and any challenges that may arise within their unique relational dynamics.