This is an early example of the trend that began in the late 1960s to produce single-topic discussions of aspects of intimate human relationships, particularly those involving activities on the margins of social acceptability. Whatever their motives, these books achieved a blend of instruction and titillation that probably ensured acceptable sales. This example fits the pattern in which a few lightly considered thoughts on its subject are liberally interspersed with 'case studies' apparently based on testimony, in which voyeurism has played an important part in the erotic activities of the individuals described. Here are included several examples which would fit equally well into discussions of partner-swapping, for which it would not be unreasonable to deduce that participants derived stimulation from the observing process. The borderline is diffuse, as indeed is the attempted definition of voyeurism itself. The book lacks the titillatory skill of, say, Gerda Mundinger in her case studies, and is this rendered somewhat pedestrian, but otherwise it makes an interesting read. ( )