Intergenerational sex between children or youth and adults was historically common, but it is understudied within the historiography of sexuality. There are three reasons that historians of sexuality should pay greater attention to intergenerational sex. First, it was common; second, discourse around intergenerational sex has been a critical site for the production of power; and third, studying intergenerational sex illuminates how sexuality is historically constructed. However, studying intergenerational sex also raises thorny methodological problems around definitions of childhood and consent, the treatment of children's agency, and how to contextualize a practice that was once considered ordinary but is now taboo. Using examples from my research on the writer and notorious pederast Norman Douglas, I address each of these methodological concerns and suggest productive approaches.