The United States of America
In the US the implementation of CSE is decided by each individual state. There has been resistance from many conservative Christian states, however other states have embraced and implemented it.
SIECUS (Sexuality Information and Education Council of the United States) is the main NGO dedicated to CSE in the United States. Below id their guidelines for a CSE curriculum in schools from Kindergarten to 12th Grade.
Click on the map below to find out more regarding the implementation of CSE in a particular state.