Despite the majority of needle-syringe sharing occurring between sexual partners, the intimate partnerships of people who inject drugs have been largely overlooked as key sites of both hepatitis C virus prevention and transmission, and risk management more generally. Drawing on interviews with 34 couples living in inner-city Australia, this article focuses on participants' accounts of 'sharing'. While health promotion discourses and conventional epidemiology have tended to interpret the practice of sharing (like the absence of condom use) in terms of 'noncompliance', we are interested in participants' socially and relationally situated 'rationalities'. Focussing on participants' lived experiences of partnership, we endeavour to make sense of risk and safety as the participants themselves do.How did these couples engage with biomedical knowledge around hepatitis C virus and incorporate it into their everyday lives and practices? Revisiting and refashioning the concept of 'negotiated safety' from its origins in gay men's HIV prevention practice, we explore participants' risk and safety practices in relation to multiple and alternative framings, including those which resist or challenge mainstream epidemiological or health promotion positions. Participant accounts revealed the extent to which negotiating safety was a complex and at times contradictory process, involving the balancing or prioritising of multifarious, often competing, risks. We argue that our positioning of participants' partnerships as the primary unit of analysis represents a novel and instructive way of thinking about not only hepatitis C virus transmission and prevention, but the complexities and contradictions of risk production and its negotiation more broadly.