“Ulrica invited me to her table. She told me that she liked going out for walks alone. Recalling a joke of Schopenhauer’s, I replied: ‘The two of us should take a walk together.'” —Jorge Luis Borges in Ulrica

Ulrica is a short story that deals with casual sex, 1970s style, published in The Book of Sand.

There has been discussion of Borges’ attitudes to sex and women.  Estela Canto, who had known Borges since 1944, asserted in Borges a contraluz (1989) that Borges’ attitude to sex was one of “panicked terror”. According to Canto, Borges’ father had arranged a meeting between his son and a prostitute, out of a concern that a nineteen-year-old Argentine boy should not be a virgin. –Wikipedia

Sex and women are two very problematic components in the fiction of Jorge Luis Borges: the absence of these two elements, which seems so casual and unremarkable, really highlights the strangeness of their exclusion. For example, scenes of sexual acts are almost totally lacking in Borgesian writing (Emma Zunz’s sexual encounter with an anonymous sailor is the most notable exception) and even the most veiled suggestion of erotic activities is limited to only a very few stories. –Herbert J. Brant, The Queer Use of Communal Women in Borges’ “El muerto” and “La intrusa”

There are, however, instances in Borges writings of heterosexual love and attraction. The story “Ulrica” from The Book of Sand tells a romantic tale of heterosexual desire, love, trust and sex. –Wikipedia