Proposition 31
Proposition 31 is a 1968 novel written by Robert Rimmer that tells the story of two middle-class, suburban California couples who adopt a relationship structure of polyfidelity to deal with their multiple infidelities, as a rationalistic alternative to divorce. The novel is presented as a case study by a psychologist supporting a fictional "Proposition 31" that would amend the California Constitution to recognize non-monogamous relationships.