Correct answer is, its what between our ears and "NOT" whats between our legs. 🙂 The Libido that gives us all the pleasure is generated in the head and without it sex can not be enjoyable. Fantasy is another part that make this so interesting and so does simple role play. Dirty talk during sex can intensify this...mind u, things need to be kept classy and not obnoxious 🙂...there is a fine line if one knows how to be on the classy side of things 🙂