Introduction
DISEASE, SEXUALLY TRANSMITTED INFECTIONS
Condomless sex, which leaves sexual partners unprotected against sexual transmission of infections and unwanted pregnancy, is still an important health-related hazard. Globally, large numbers of people attain sexually transmitted infections (STI’s) on a daily base. For example, the European Centre for Disease Prevention and Control (ECDC, Determinants of condomless sex have been investigated in studies using global, situational, event-level, and experimental designs. Compared with global designs, situational and event-level studies enable investigating contextual determinants of condomless sex. However, these designs do not allow for causal inferences regarding the effects on condomless sex of the factors of interest, while experimental study designs do (Palfai & Luehring-Jones, Alcohol use and sexual arousal should therefore both be taken into consideration when trying to understand why people exhibit unsafe sexual behavior. Although higher alcohol expectancies were found to predict stronger intentions for condomless sex (Fromme et al., 