ooh I love having insomnia...
Its all well and good saying as a parent you want to be the one to teach your child about sex and all that it entails.. but it doesnt work.
All children deserve to be given broad and unbiased facts. If a parent has been in only one good solid relationship, then they have no experience to educate their child about domestic violence and how to spot the signs. If a parent has been in multiple disfunctional relationships, then they have experience, but may not even know themselves what constitutes a good healthy relationship. Their kids do deserve to be told.
You as a parent may not believe that a gay lifestyle is right, but that doesnt stop your child being gay.
Once your child starts to reach puberty, they are entitled to their own beliefs and their own choices within reason and within the law.
If sex and relationship education is part of the curriculum, covering health, personal safety, boundaries, then it enables that child to be better equipped and more confident to deal with what might be thrown at them over the next few years. It should be taught fairly and without prejudice, and it should be impartial.
By all means as parents, explain to your children about how pro-creation occurs, but allow your child to have the opportunity to make their own choices rather than trying to enforce your beliefs onto them.