As someone who has taught sex education for 36 years to students age 11-18 I think I am a bit of an expert on this. I was also a member of the county PSHE Team (Personal, Social, Health Education) a big part of which was Sex Education.
I think all children should receive good sex education and that should be age appropriate.
In younger children of Primary School age this should be around life cycles of animals, relationships and changes that take place in the body.
In secondary school this progresses into the fundamentals of human reproduction and would cover topics such as menstruation, masturbation and relationships.
By fifteen such topics as contraception, STDs, sexting, respect, homosexuality, human sexuality, sexism, dealing with emotions, love, relationships, inappropriate sexuality, pornography, pregnancy and abortion would be appropriate.
17 and 18 year olds would have detailed discussions on such things as the…