If a parent comes to you and says "I don't want my child learning sex ed," start by asking "Why? I would love to hear more about your concerns so we can work through this together."
I also suggest reminding them, "Would you rather your child learn from a trusted adult, or would you rather they get information from their friends or from the internet - which does not guarantee the content is accurate or safe?"
Make it a discussion, don't shut it down. Let's have collaborative conversations, even if we don't see eye to eye at first.
Teachers have an obligation to ensure family values are respected and upheld - teachers are encouraged to acknowledge that families and individuals have different beliefs and values that we should respect. Teachers also have an obligation to ensure their students are safe and healthy, which means discussing subjects that are based on the laws, rights, and human rights in Canada (e.g. marriage equality). This is outlined in our Ethical Standards by the Ontario College of Teachers (OCT).