During the early stages in the womb all foetuses are female up until a point in which a certain grouping of hormones are introduced which then chemically decide the sex of the foetus, either keeping it in its original position to grow as a female, or by aiding the development of the Y chromosome which allows for male gender assignment. So the nipples are just a by product of our early ****** development.
That's a very simplified explanation.
That's why guys with sensitive nipples have female tendancies, mine are sooo sensitive and I'm slightly bi-sexual.
There has been scientific research into sensitive nipples on men, it concluded that it's because they feel unwanted, useless, have no sense of purpose, and therefore tend to have low self esteem! If you have sensitive nipples, just lightly compliment them every now and again, just to try and reassure them!
In the beginning we were all androgynous and its vestigial, like an appendix or Will E.'s brain.
In the beginning we were all androgynous and its vestigial, like an appendix or Will E.'s brain.