Rose Cook (plaintiff) and Donald Cook (defendant) lived together between 1969 and 1981. Rose and Donald never married, but they held themselves out as husband and wife. During their relationship, Rose and Donald agreed that they would pool their earning and share equally in their joint accumulations. To this end, they maintained various accounts in the names of “Rose and Don Cook” as joint tenants, using these funds to pay for household expenses. In 1981, Rose left Donald, retaining only a car and small amount of money, while Donald kept the rest of the couple’s property. Rose brought suit against Donald, claiming breach of their agreement. The court of appeals found in Donald’s favor, concluding that division of property acquired during nonmarital cohabitation, pursuant to an agreement between the parties, was not permissible under Arizona law.