This study investigates how capuchin monkeys (Cebus spp.) navigate cooperative decision-making in the prisoner's dilemma task, focusing on the influence of social relationships and decision-making order. Analyzing data from individual trials across multiple sessions, I demonstrate that capuchins adjust their choices based on their partner's previous and current decisions, as well as the quality of their social relationship, measured by grooming frequency. Notably, the impact of these factors varies depending on whether the capuchin is the first or second to choose in a trial. Our findings reveal a nuanced strategy where capuchins exhibit both matching behavior and strategic variation in response to their partner's choices. Despite challenges in capturing all behavioral variability, our study underscores the significance of social bonds and decision-making dynamics in shaping cooperative interactions among capuchin monkeys, contributing to broader understandings of animal social cognition and cooperation.