Using discussions, and published and unpublished texts, this article shows that reference to the nymph in the work of Pierre Fédida, following the example of Nabokov’s Lolita, was part of an important theoretical construction regarding temporal representation in the Oedipus complex. The latter may be envisioned from the perspective of aging or of rejuvenation. This debate is retraced here, with an explanation of the background behind the research. P. Fédida constructed a nymphette complex that is useful for diagnostic purposes. This is an interesting idea in psychoanalytical theory that ties in with the work of Freud and Lacan on the signification of the young girl in psychical life, and more particularly in male psychology. The young girl receives a phallic over-investment because of the castration anxiety she provokes, inspiring a horror of the mature woman, and at the same time helping to overcome this by introducing the figure of a girl who plays on her pre-maturity. But it is not easy to define the age either of the nymphette or of person she’s intended for. Clinical examples allow for relative flexibility in determining the real age. The nymphette complex rests therefore on a paradoxical situation.