Timothy "Tim" F. LaHaye was an American evangelical Christian minister, author, and speaker, best known for the Left Behind series of apocalyptic fiction, which he co-wrote with Jerry B. Jenkins.
He has written over 50 books, both fiction and non-fiction.
If you have high expectations for your children, if you want to be diligent in teaching them God's plan for sex and the family, if you want an age-based guide from a solid Bible foundation, this book is what you're looking for. I hope I can be as diligent with my children as this book describes to give them the best chance at a marital physical relationship that is fulfilling and free from guilt or regret.