Can man lactate? According to this Scientific American article, the answer is yes:
Newman explains that medical disruptions involving prolactin, the hormone necessary to produce milk, have resulted in spontaneous lactation. Thorazine, a popular antipsychotic used in the mid-20th century, impacted the pituitary gland—the pea-size endocrine gland located near the base of the brain—often causing it to overproduce prolactin. If prolactin levels remained high, milk could follow. According to Newman, lactation is listed as a possible side effect of the heart medication digoxin. A pituitary tumor could also induce milk production: "It would be the same reason—increased prolactin levels&mdashin the one case drug-induced, in the other due to a tumor or some other sort of neurological problem."
In a 1995 article for Discover titled "Father's Milk," Pulitzer Prize-winning author and one-time physiologist Jared Diamond reconciles the nipple stimulation and hormone quandary, pointing out that such stimulation can release prolactin. He also notes that starvation—which inhibits the functioning of hormone-producing glands as well as the hormone-absorbing liver—can cause spontaneous lactation, as observed in survivors of Nazi concentration camps and Japanese POW camps in World War II. "The glands recover much faster than the liver when normal nutrition is resumed," he writes, "so hormone levels soar unchecked."
Link - Thanks Scott Rosenblum!