Biological evaluation of sperm is a central part of the process of Assisted Reproductive Technologies (art). This test known as sperm provision is performed through masturbation. An ethnographic study was carried in two major French hospitals and showed that shame, discomfort, strain and disgust were often associated with the practice of masturbation in a place and context considered as inappropriate. The confusion between the medical and the sexual domains, the impossibility of de-sexualizing a practice still considered as taboo, and the infertile nature of sperm could be at the source of the disgust toward sperm when manipulated in a medical context.