In the scientific literature on fertility and assisted reproduction, and in the corresponding area of clinical practice, increasing attention has been paid to two groups: people living with the human immunodeficiency virus (HIV) and gay men. However, research on fertility in the context of HIV focuses almost exclusively on heterosexual couples while studies on non-heterosexual reproduction rarely mention HIV – despite the fact that, in many western countries, HIV prevalence among men who have sex with men (MSM) is higher than ever before and MSM are the only group where new HIV infections are on the rise. This article identifies links between reproduction, HIV and homosexuality, showing that, historically, they are closely intertwined, which has important implications for current issues facing HIV care and fertility services. Considering sex and parenthood as two different but related kinds of intimacy and kinship, the article discusses the dual role semen plays in sexually transmitted infection and in assisted reproduction. It reflects on the future of sperm donation and HIV prevention, asking whether two challenges that potentially face healthcare and medicine today – the shortage of ‘high-quality’ sperm and the ‘surplus’ of infected semen – could be addressed by a greater exchange of knowledge.