The Kerista Commune was a 📝San Francisco, CA intentional community, active from 1971 to 1991, that practiced closed group marriage and coined the terms polyfidelity and compersion.
Founded by John Peltz "Bro Jud" Presmont and a small circle of followers, Kerista grew through the 1970s and 1980s into a Haight-Ashbury community of a few dozen members organized around "Best Friend Identity Clusters" — closed groups of equal partners who rotated sleeping arrangements on a fixed schedule so that every pairing stayed balanced. It called this arrangement 📝polyfidelitous: many partners bound by a shared, group-level fidelity rather than by couples.
Alongside polyfidelity, Kerista contributed 📝compersion — the word for the joy felt at a partner's other connections — to the vocabulary that later 📝Consensual Non-Monogamy (CNM) communities adopted. The commune also ran a profitable Macintosh computer business, Abacus, which supported it financially. Kerista dissolved in 1991 amid disputes over money and over Presmont's authority, but its coinages outlived it and remain in common use across contemporary non-monogamy.