Erotic lactation between partners or an adult nursing relationship may develop from natural breastfeeding of a baby. During the lactation period the partner starts to suckle on the female breast, and continues after the baby is weaned off. Milk production is continually stimulated and the milk flow continues. According to the book "Body parts: critical explorations in corporeality", adult nursing may occur when an "individual, usually a mother, may choose to continue lactating after weaning a child, so that she avoids the significant physical challenge that inducing lactation can entail."