Parental control behaviors are suggested to be related to emerging adult outcomes, such as risky sexual behavior. Although parental control behaviors are more likely to be considered protective against risky sexual behavior, the relation between parental overprotection and risky sexual behavior is unclear. Furthermore, parental overprotection may influence peer selection and prosocial behaviors in emerging adults, which may in turn influence outcomes of risky sexual behavior, as suggested by primary socialization theory. Thus, the current study investigated the relations among paternal and maternal overprotection, emerging adult peer alienation, and risky sexual behavior, and expanded on these relations by examining gender effects of both parents and children. The sample consisted of 505 participants (228 males and 277 females) ranging in age from 18 to 25 years. Analyses were conducted with AMOS path analysis and indicated that peer alienation mediated the effect between both maternal and paternal perceived overprotection and risky sexual behavior, but more strongly for males, suggesting moderated mediation. Overall, parental overprotection may be protective against risky sexual behavior via pathways that are harmful such as peer alienation, thus recommending research continues to clarify the nuances of these relations.