This paper focuses on the cultural transformations of the concepts of love and intimacy through the "One True Pairing" phenomenon in the Brazilian Fan Fiction community called "Nyah! Fanfiction". In such community, amateur fiction literature is produced by teenagers and young adults, mainly focused on love relationships, pairing their favorite characters as romantic couples. Thus, this paper is guided by the following question: to what extent those stories, which focus on love and intimacy, update the concept of love relationships and intimacy on these young writers and readers, and how the interactions happening in that community involving those stories can contribute to the realization of those transformations. Like so, intending to make explicit the different modalities of love relationship and how they are used and updated in the stories produced in the community, we have selected five amateur literature pieces, based on the "Harry Potter" series of books and movies, published in the community between 1st of January, 2017 and 31st of March, 2017 and categorized following the method established by Bardin. Each piece, as well as the community interactions created around them like reviews and discussions, is analyzed following the semiotic and pragmaticistic theory proposed by Charles Sanders Peirce, using Anthony Giddens' findings about the transformations of intimacy and love relationships in modern society as the foundation for our categories and also for our analyses. Among the results obtained, we should emphasize that those young writers aren't limited to a single modality of love relationship in their works, instead, they mix and match different forms of love to produce their narratives. At the same time, the stories present a strong presence of the "passionate love" and the "romantic love" defined by Giddens, even in more modern and diverse fictional relationships, signaling the importance of sexual attraction and marriage for the construction of a love relationship for those young writers. The results of the analysis of the community interactions around those stories reveal effects in all three of the cognition categories defined by Peirce, making clear that those amateur pieces of fiction, based on their loved characters and media products, do produce lasting effects on the members of the community, effects which, in due time and following the theory proposed by Peirce, can become transformations in their habits and beliefs. The reflection about the possibilities of those transformations of belief, conceptions and habits of love, as well as about the processes operated in a community of amateur writers, and also about new methodologies for gathering data from Internet-based communities and analyzing it constitute the importance of this research.