Why can't i have an orgasm through penetration only orally?

Unnecessary secrets: Many females have no orgasm from penetration or intercourse alone. This is a terrible secret that should not be secret. But, it is. Many couples have to incorporate clitoral stimulation into their love making. Partners appreciate knowing this and should be eager to participate in this mutual sexual activity. There is a book published by a group of women trying to teach this. I often recommend it.