In this study, we used an exploratory methodology to determine what cultural models African American emerging adults use to understand infidelity/cheating. Cultural models are defined as "cognitive schema[s] that [are] intersubjectively shared by a social group" (D'Andrade, 1987, p. 112). We interviewed 144 participants ages 19-22 from three geographically distal sites. Qualitative analysis was conducted using NUDIST and In Vivo Analysis, a form of Grounded Theory. Among those in a main (dyadic) relationship, 37% of females and 57% of males stated they had been unfaithful to their main partner during the past month. We identify five cultural models defining 1) the nature of infidelity, 2) reasons for infidelity, 3) techniques for managing side (extra-dyadic) partners, 4) means of investigating suspected infidelity, and 5) condom use in main and side relationships. Our findings suggest that stressing condom use in side partner relationships may be a particularly effective means of HIV/STI prevention in this high-risk population.