"Ladies, if you want to crush your man's soul, stop giving him oral sex. If you want to blow his mind, become skilled at it," Matt Titus advises people in Why Hasn't He Proposed, the book he co-authored with wife Tamsen Fadal. That's not all... he goes on to explain how you can become "proficient at this particular job" through videos, books and even "classes that teach you trusted techniques".