Gender orientation is not either-or, it's a spectrum and there are many bisexuals as well as people who look one sex on the outside but are the other on the inside. In addition, indeterminate gender was one of the more common birth defects I saw when I worked as a nurse's aide in a newborn nursery. Not to mention the fact that libidos come in a spectrum too, from those who are hot-to-trot every moment, to those who happily do without sex their whole lives.