After conducting research, I was unable to find specific information on notable events or developments in sexual education in Belgium exclusively related to 1991. However, I can provide some general context on the state of sexual education in Belgium during the early 1990s.

During this period, Belgium was experiencing a growing awareness of HIV/AIDS and other sexually transmitted infections (STIs). This led to an increased focus on sexual education and prevention initiatives in schools and communities.

Over the years, sexual education in Belgium has become more comprehensive and inclusive, addressing topics such as relationships, consent, and LGBTQ+ issues. The current approach aims to promote healthy attitudes towards sexuality, relationships, and gender, while also preventing STIs and unplanned pregnancies.

In the early 1990s, sexual education in Belgian schools was primarily focused on providing information about human anatomy, reproduction, and the prevention of STIs. The approach was often biological and medical in nature, with an emphasis on abstinence and safe sex practices.

In Belgium, sexual education has been a part of the country's educational curriculum for several decades. The approach to sexual education has evolved over the years, reflecting changes in societal attitudes, values, and laws.