Behaviors that pose threats to safety and health, including binge drinking and unprotected sex, increase during a week-long break from university. Understandings with peers regarding these behaviors may be important for predicting behavior and related harms. College students ( N = 651; 48% men) reported having understandings with their friends regarding alcohol use (59%) and sexual behavior (45%) during Spring Break. These understandings were to engage in behaviors characterized by risk (e.g., get drunk [23.5%], have sex with someone new [5.2%]) and protection (e.g., drink without getting drunk [17.8%], use condoms [15.8%]). After controlling for previous semester behavior and going on a Spring Break trip, Get Drunk Understandings predicted a greater likelihood of binge drinking and alcohol-related consequences; No/Safe Sex Understandings predicted condom use; and Sex Understandings predicted not using condoms. Understandings with friends regarding Spring Break behavior may be important proximal predictors of risk behaviors and represent potential targets for event-specific prevention.