Background Social and sexual distancing (ie, abstaining from sex with persons outside one's household) was important in the control of the COVID-19 pandemic. Compliance to distancing measures can change over time. We assessed changes in compliance to the sexual distancing measures during five periods of the COVID-19 pandemic in the Netherlands. Methods Between November 2021 and March 2022, we used a structured questionnaire containing questions about sexual behavior and factors that could have influenced compliance with sexual distancing. Variables related to sexual behavior were measured for 5 periods, before and during the pandemic, delineated by imposement and relaxation of lockdown measures. Results Eight hundred seventy participants (predominantly MSM) completed the questionnaire. We found that compliance to the sexual distancing measures decreased over time. The number of casual partners was highest after the lockdown measures were relaxed for the second time (April 2021 to March 2022), and even higher than before the first lockdown. Factors positively associated with sexual distancing compliance were: having confidence in the information provided by the government and experiencing less or similar need for physical contact compared with before the pandemic. Factors that lowered compliance over time were: previously having had COVID-19, perceiving the lockdown measures as overstated, having sex with casual partners and similar drug use during the pandemic as before. Conclusions Our findings suggest that sexual distancing measures are difficult to maintain for a long period. Other measures, such as confinement to a small network of known partners, might be more effective for longer pandemics in minimizing the spread of infectious diseases.