Guided by communication privacy management theory, this study examined rules in a friends with benefits relationship for established adults (30–55 years old). The most common rules from the sample (N = 240) included prevention of overlapping lives (i.e. cannot meet family) and the presentation of the relationship (i.e. keep the relationship a secret). Explicit rules were associated with greater relationship satisfaction, intimacy, and trust as compared to implicit or no rules. Rule specificity (i.e. explicit, implicit, no rules) did not impact commitment, love, passion, or sexual satisfaction. These findings offer unique insights into casual sex relationships for a non-college-aged population.