It is important for psychoanalysts to educate themselves about variant forms of sexual expression, such as the fact that heterosexual cross-dressers virtually never give up their preference because of psychotherapy. A more realistic therapeutic aim is to help the couple negotiate a workable relationship. Infidelity, too, has many possible definitions that can be negotiated by the couple. In some instances, the wish for extramarital contact may be motivated less by sexual desire than by other psychological needs, such as the fear of death and the wish for immortality. The sustenance of sexual passion in a long-term relationship is a phenomenon that requires greater understanding. Variation in lifestyle, as well as modifications in characterological ruts, can often help revive passion.