Queer relations in the novels of Eça de Queirós have elicited little critical attention. This article identifies a series of such relations that exceed the accepted definitions of friends, comrades, and siblings, undermining the language of kinship and patriarchy. I propose that weak paternity in Eça is in part due to an erotic indeterminacy in relationships that leaves the father's name unintelligible. This line of enquiry therefore brings together existing scholarship on paternity, homoeroticism, and incest. By depicting the disastrous consequences of an inadequate kinship structure, Eça urges a re-evaluation of the vocabulary and policing of desire.