What do children know about sexuality? And how do they experience it? This is the starting point of SexAFIN, the action-research project on affective-sexual and reproductive education in educational communities. The research is promoted by the AFIN Research Group of the Anthropology Department at the UAB, which is dedicated to research on families, reproduction, childhood, and sexuality. SexAFIN was established in 2017 in two schools in Gelida with children in 2nd, 4th, and 6th grades. Since 2019, it has expanded to include children and young people from 13th to 4th grades of Compulsory Secondary Education from around forty public and private schools throughout Rio de Janeiro (Brazil) and KwaZulu-Natal (South Africa).