"in explaining sexual dreams I would have to become deeply involved in the still unsolved problems of perversion and bisexuality, and so I kept this material for another occasion"

   Freud would explore these ideas concerning sexuality further in his Three Contributions to the Theory of Sex, first published in 1905.  As well as elaborating his theory of the 'Oedipus complex' (See note to page 201), he further explores the controversial idea that discrimination between sexual partners and practices is behaviour a person learns throughout their development, overlaying an "original bisexuality".

 

Online edition of Freud's 'Three Contributions to the Theory of Sex', translated by A.A. Brill, (1920)