Nipple and breast stimulation of women are a near-universal aspect of human sexuality, though nipples in males are not as sexualized.
"Milk fetishism" and "lactophilia" are medical, diagnostic terms for paraphilias and are used for disorders according to the precise criteria of ICD-10 and DSM-IV.
Breasts, and especially nipples, are highly erogenous zones, for both men and women.
Erotic lactation is sexual arousal by breastfeeding on a woman's breast.
Depending on the context, the practice can also be referred to as adult suckling, adult nursing, and adult breastfeeding.
This can be done by regularly sucking on the nipples (several times a day), massaging and squeezing the female breasts, or with additional help from temporary use of milk-inducing drugs, such as the dopamine antagonist Domperidone.
It is not necessary that the woman has ever been pregnant, and she can be well in her post-menopausal period. As long as there is regular breast stimulation, lactation is possible.
She may have difficulty beginning lactation, so she supplements the infant's suckling with that of a partner.
Or there are cases where breastfeeding was interrupted for an extended period of time as a result of infant prematurity, infant absence, or mother's illness (taking prescription medication).
Practitioners sometimes refer to themselves as being in an adult nursing relationship (ANR).