The COVID-19 pandemic drastically changed people's lives. It had consequences at the individual and social level, changing the way we relate to each other. The behavioral immune system predicts that certain constraints will exist in different aspects of sociality when faced with the risk of contagion from pathogens. In this paper, we examine the hypotheses specifically evaluating changes in the sociosexuality of young men. We compared data from two studies carried out by the laboratory team before and during the pandemic (in-person and online data by Qualtrics®). We reached an N = 879 young men who answered a sociodemographic questionnaire and the Multidimensional Sociosexual Orientation Inventory. The results we obtained point to a significant decrease in long-term sociosexual orientation but not in short-term sociosexual orientation, as we had predicted. In addition, we found a reduction in sociosexual desire (measured as sexual fantasies) and differences in sociosexual behavior (number of partners in the last year) between the period before the pandemic and the pandemic itself. In addition, we carry out analyses with a reduced sample to test our hypotheses based on the perception of contagion risk (measured by a survey from OMS). We find changes are maintained at the level of sociosexual desire and sexual behavior but mostly in those individuals with a greater perception of the risk of contagion. The hypotheses derived from the behavioral immune system regarding the decrease in sociosexuality in a context of risk of contagion by pathogens, as was the case in the initial period of COVID-19, are corroborated only in terms of desire and behavior, which suggests a certain stability in attitudes. These findings will allow us to understand better how sociosexuality is affected when there are contexts of high risk of contracting a pathogen such as COVID-19.