Wet nursing, or cross-nursing, occurs when a woman breastfeeds another person's baby. It’s a topic that is rarely discussed, but is commonplace in the lives of many mothers. A new mom may want to engage in this sort of practice if they're not able to breastfeed their baby, but still want their baby to have milk from the breast. Others looking into the service include couples adopting newborns and same-sex couples who want their children to have the experience of breastfeeding.