What I read before was that Freud got his theory about bisexuality from his one time friend, Fliess, but never gave him the credit. Here is a link to an interesting 4 or 5 page paper by Edward J Kempf. In it he tells about going and meeting with Freud and discussing the method he was using with his patients.

http://schizophreniathebeardedladydi...empfMay191.pdf