Teachers are better educators
Teachers have committed their lives to educating children and teens. They can communicate far more effectively than parents.
Teenagers are always going to have sex. By putting sex education on a curriculum, no child gets left behind and is left vulnerable, without the knowledge to make informed decisions and protect themselves.
Teenagers are always going to have sex, so we may as well accept that and make sure they are as safe as possible by providing sex education in schools. Leaving it up to parents could lead to some teenagers engaging in sexual activity without being aware of the dangers.
Studies indicate that there is no existing form of sex education that reduces the number of teenagers engaging in sexual activity.  Whether they receive abstinence-only sexual education instruction, no instruction, or a comprehensive class in sexual education and relationships, teenagers engage in sexual activity at the same rate and frequency. The implications of this mean that instead of pretending teenagers aren’t having sex, we should accept that they are and focus our attention on ensuring they are aware of the necessary precautions to ensure a safe and happy sex life. This means putting comprehensive sex education programs on the school curriculum. In doing so, governments and educators can ensure that no child is left vulnerable to sexual exploitation and abuse by not having the knowledge required to protect themselves. Taking it out of the parents’ hands means that everyone gets the same access to information. and no child is left behind.
The school is the realm of the academic and the home is the realm of the spiritual and pastoral care. Sex is not an academic subject. It is a moral, spiritual, and ethical matter. Therefore, the responsibility and choice of when and how much to tell a child or teen should be the parents’ alone.
[P1] Placing sex education in schools gives all teens access to the same information. [P2] Therefore, nobody is left vulnerable by not having access to the information required to protect themselves. [P3] Therefore, sex education should be taught in schools.
[Rejecting P3] The school is the realm of academic instruction. Home is the realm of spiritual, moral and ethical instruction. Sex education is a moral and ethical concern. Therefore, it should be kept out of schools.