Public-private cooperation is vital for emergency stocks, yet complex behavioral characteristics of governments and suppliers often affect system reliability. Existing research has mainly examined supplier loss aversion, with limited attention to government inequity aversion. This paper investigates how to strategically reserve and procure emergency supplies under the roles of supplier loss aversion and government inequity aversion. We develop an option contract-based emergency stockpiling model that incorporates a loss-averse supplier and an inequity-averse government. Moreover, comparisons between the decisions yield the boundary conditions for supplier understocking and overstocking. The conditions for humanitarian channel coordination under both disadvantageous and advantageous inequity aversion are derived, with some overlapping and others differing between both situations. A case study using laboratory simulations is conducted. The results indicate that higher loss aversion and optimism levels decrease the supplier's best reserve quantity; disadvantageous (advantageous) inequity aversion increases (reduces) the government's optimal purchase of physical options. The boundary conditions for supplier understocking and overstocking depend on the interaction between government inequity aversion and supplier loss aversion. Finally, some targeted managerial insights are proposed to coordinate the humanitarian supply chains, select appropriate suppliers, and evaluate the behavioral preferences of participating members.