This article studies Cartas de um sedutor, by Hilda Hilst. Our goal is to analyze the representations of dissenting sexual identities present in the digesis of this novel. The hypothesis we propose is that in this Hilst text there is an intention to destabilize the heteronormative sexual order, through the presentation of queer characters, whose performance demonstrates that generic identities are not fixed or stable. In addition, this book posits the formulation of a sexual ethic, which aims to question sexual practices normalized by heterocentric thinking. To develop our analysis, we rely on the theoretical contributions of narratology, gender studies and queer theory.