It is a fallacy to think that male nipple serve no purpose. They serve the same purpose in many males that the female clitoris does. That is they are extremely sensitive errogenous zones. Some men may not have sensitivity in their nipples and some nay not want to admit that their nipples are sensitive (thinking it is an exclusively gay trait). Some biologists say that males even have milk glands usually underdeveloped and non-functioning in that capacity. But as errogenous zones male nipples are often as sensitive as female nipples. I am 100% heterosexual and can attest to the errogenous quality of my nipples. After all, the clitoris serves no other function than to bring pleasure to the female. Male nipples have the same function.