Viewing sexually explicit materials (SEM) has become a normal sexual experience for many adolescents, and there are those who perceive that SEM has impacted them in a positive manner. There are growing concerns among parents, educators, and medical professionals over adolescents' use of SEM, however, which include fears that SEM distorts young people's views and understanding of human sexuality. Given the gap in the assessment of associations between SEM use and perceived SEM reality across time, this study used a panel sample of 875 Croatian 16-year-olds (67.3% of female gender) to estimate parallel latent growth in SEM use and SEM realism over a 23-month period. We observed a significant increase in SEM use and a significant (non-linear) decrease in SEM realism in both genders, but no statistically significant correspondence between the two constructs. It has been assumed that adolescents will dismiss SEM as unrealistic once they become sexually experienced. This hypothesis received only limited support, suggesting the role of other, unmeasured, moderators, but also the importance of expanding the currently limited conceptualization and measurement of SEM realism.