This is a really thorny issue. In a perfect world children would have no qualms about asking their parents for guidance in the realm of sex.
Yet in the real world how may parents can answer the questions or provide the guidance?

How would you guide a a child through its first intercourse?
Do you think they want you to stand there watching while they get laid for the first time?
And if voyeurism was not your intended meaning, then I can only conclude that you meant incest, which I doubt you meant; that is another bucket of worms.

What then? There is no practical way that I can envision for a parent to guide a child through its first sex encounter, unless the parent is either committing incest or voyeurism.

The only practical solution is to enlist the aid of caring pedophiles, such as ourselves, to initiate the child into the intricacies of love in all of its manifestations.

You would not ask an illiterate to teach your child to read, nor would you ask an anumerate to teach your child math. Why then would you expect them to learn love from someone who is also a beginner?

Nay, children should learn love from an experienced adult who could make it a beautiful experience for them, the way it is done in any truly civilized culture.