The phenomena surrounding the pains commonly related to both first coitus and delivery have been addressed rather poorly in previous work, as regards their evolutionary aspects, during the investigation of human sexuality and reproductive behavior. In particular, the function of the hymen and the significance of defloration are largely misunderstood. The present paper aims to analyse the meaning of these two female physical pains in an evolutionary context. Accordingly, childbirth and defloration pains are hypothesized to manifest an adaptation designed to increase inclusive fitness in human evolutionary history. Clearly, the significance of pain as a message is essentially emotional. Indeed, the intense sexual emotions that may precede and/or follow the pain, the breaking and bleeding of the hymen during the first complete sexual act may generate distinctive strong feelings on/from each side of the newly formed couple. As to labor pain, both the shared intimacy with the mother and the emotional background during confinement may create mutual solicitude among the protagonists (i.e. midwifes, father, mother). Such feelings or attitudes may subsequently turn out to be beneficial to all of them, and more particularly to the newborn. As a general consequence, it appears that the two physical pains under consideration may have behavioral implications, in the sense that they contribute to increasing the stability of the connection between partners and thus, indirectly, to the welfare or even the survival (especially in former times) of the newborn child.