This article examines the ways that plebeian women confessed to concubinary relationships in seventeenth-century Lima. Part One reviews complaints brought by casta and enslaved concubines to enforce matrimonial promises. Part Two analyzes the imprecise laws and policies of the canonists on concubinage. Part Three considers the Church’s inquisitorial function in policing interethnic intimacies, given the virtual synonymity of illegitimacy and concubinage. The article assesses the marriage–concubinage dichotomy from the perspective of women who, given their ethnic and social position in colonial society enjoyed limited legal standing vis-à-vis elite women, but conversely exercised greater sexual freedom in forming and dissolving partnerships.