"In Hook-Up Sex you and your partner use each other's bodies for your own pleasure. It can be extremely intense and arousing, especially when you feel lust towards a new partner. There's a place for this kind of sex, but it's also the most primitive, least evolved form of sex. It reflects the purely animal part of being human -- our physiological needs and impulses. We share those with other animal species. From a human standpoint, though, it's mostly void of relationship beyond the physical connection; a form of playing through using each other's bodies."