The promotion of unhealthy habits in gay, lesbian, and straight intimate partnerships

► Research shows that marriage has important positive consequences for health habits. ► Few studies examine how unhealthy habits are promoted in marriage. ► This study examines the mechanisms through which gay, lesbian, and straight partners promote one another's unhealthy habits. ► Three mechanisms emerge: unilateral diffusion, bilateral diffusion, and a discourse of personal responsibility. ► Analysis outlines how these processes operate differently for men and women across gay, lesbian, and straight relationships.