Sexuality in Medieval Europe: Doing Unto Others, by Ruth Mazo Karras is probably the most recent and up to date study of medieval sexuality. However, Karras argues against applying labels such as "heterosexuality" and "homosexuality" to the medieval period and argues instead that medieval sexuality should be seen in terms of active, passive and celibate. There is discussion of male/male and female/female sexual activities, but it is in this context rather than the modern spectrum of sexuality.