This article situates Widl/Mozart's Apollo et Hyacinthus (K. 38; 1767) in its historical and original performance context to counter claims that this is a heteronormative work. Widl recast a love story more widely known from Ovid's Metamorphoses, and W. A. Mozart supplied the music for this intermedio. I trace the different versions of this myth in the texts of Ovid and Widl. I consider the connections between Apollo et Hyacinthus and Clementia Croesi, the "masque" with which this intermedio was interspersed in performance. First produced at the Salzburg Gymnasium with an all-male cast, there is a confusion of gender and a persistence of homosexuality written into this work and its initial performance. I study contemporary attitudes towards sexuality and morality to unpack how eighteenth-century audiences would have read this work. These disparate threads combine to reveal the ambiguity, the polymorphous perversity (in Holsinger's sense), of Apollo et Hyacinthus.