Millions of users now engage in sexual and romantic interactions with AI chatbots, from dedicated companion platforms such as Replika, Ourdream.ai and Character.AI to general-purpose large language models such as ChatGPT, whose developers have recently discussed permitting erotic content for verified adults. These developments constitute what McArthur (2022) terms second-wave sextech, in which the artefact itself becomes the focal point of sexual engagement. Contemporary philosophical debate on second-wave sexual technologies is organized around three dominant positions: instrumentalist, abolitionist feminist, and polysemic. Each is primarily concerned with the ethical permissibility of their design and use. We argue that all three share a significant shortcoming: they fail to address the conceptual pressure that AI-mediated sexual technologies exert on established categories within the traditional philosophy of sexuality and on everyday concepts people use to make sense of their sexual subjectivity, activities and relations. Current philosophical discussions neglect the question of how these technologies may require us to revise such notions as sexual activity, sexual partnership, intentionality, objectification, and the ontological status of technologically mediated sexual experience. This neglect arises from an insufficient appreciation of the co-constitutive relationship between sexual technologies and the concepts through which we understand sexuality. Drawing on a work in conceptual engineering and techno-moral change, we demonstrate that earlier sexual technologies have already occasioned substantial conceptual and normative shifts, and that the current proliferation of AI-mediated sexual interactions is likely to intensify them. The paper advances two claims: that philosophical inquiry into AI-mediated sexual technologies must engage the broader tradition in the philosophy of sexuality, particularly regarding the ontology of sexual acts and sexual subjectivity; and that an empirically informed approach, drawing on experimental philosophy and established empirical disciplines, is warranted to investigate how these technologies reshape broader conceptualizations surrounding sexuality.