There is very little theoretical literature on bisexuality per se. Most often it is considered as a special facet of homosexuality. I think the topic merits discussion in its own right for three reasons. Most of the "successes" in treatment of homosexuality were actually cases of "bisexuality", that is, patients were married or had heterosexual experience at the start of treatment. Little more is said about treatment outcome in their cases and generally we do not know what their initial erotic preferences were. Therapy is more important if it can change a man who prefers men or who is truly ambisexual and prefers both men and women into a heterosexual. Second, theoretical papers are divided on the belief in the existence of the bisexual. If one uses overt behavior as a criterion, bisexuality appears to be quite prevalent. However, if one uses erotic preferences or reproductive functioning it seems to be nonexistant. The third reason a special chapter is devoted to bisexuality is that clinically at least, they are considered to be less disturbed than exclusive homosexuals. In contrast I have found these men to be much more emotionally disturbed than exclusive homosexual patients and I believe the usual treatments applied to changing them into heterosexuals are not only misguided but antitherapeutic.
The word bisexual is ambiguous and at least three overlapping meanings have been applied to the term: relating to both sexes in overt behavior, in erotic preferences, and in reproductive functioning.