flighty dancer

In one possibly apocryphal story, Hartel asked the emperor to imagine a wonderful but flighty dancer who ran away from the Vienna theater but then wanted to to return: would the emperor take back such a favorite? Franz Josef, who for many years had maintained a close relationship with a famous Viennese actress, Katharina Schratt, reportedly laughed, and consented to Boltzmann's reappointment. - Boltzmann’s Atom