Based on the case of “Felix,” which led to the concepts of internal objects and unconscious fantasies, and the case of “Ilse,” in which the focus was on the Kleinian concepts of feminine sexual identity, the author explores material from the analysis of “Willy” (aged fourteen). In this analysis, Klein illustrates and conceptualizes — as in the cases of Felix and Ilse — that revisiting the early Oedipal phase during adolescence is the condition  <i>sine qua non</i> for the joint integrative development of psychic bisexuality and “psychic puberty.” Klein relates this work to the concepts of the feminine phase common to both sexes, of combining parents, and of male homosexuality.