Why do men have nipples?
494055
So they don't look weird in bathing suits.  If you want them, get them.  If you don't really care that much, I wouldn't do any kind of surgery without really needing/wanting it.
62582
Many scientists believe that male nipples are an evolutionary vestige which is simply the result of males and females shareing virtually identical genetic structures.  Some evolutionists belief that evolution has not phased male nipples out because there is no evolutionary advantage to phasing them out.  Also, male nipples do serve a limited function in sexual arrousal.  Further still, male lactation does occur, though rarely, and is no doubt the result of the simularities in the genetic code with females.
414466
ladies nipples getting hard is just the same as when a guy gets a boner. that happens when you're horny
8533
Many answers.  Some guys like breasts because it reminds them of a safe place when they were children in the arms of their mothers (kinda gross, I know).  Others might like boobs because they like the idea of being able to touch that sensitive part of a girl that others guys can't.  You also have guys who likes to think of boobs as location of a kinky act.  The reasons are many.  I say they want to look, let them.  Once they start looking, we girls can get whatever we want from them :P
22705
We are classified as mammals.  Mammals feed their young by the use of breast milk.  All male and female animals have nipples (what was God thinking?), but only the females have the hormones and additional physical items necessary to activate the lactation process.\n\nGender differneces stem from the X/Y genetic differences.  The rest of the body (including nipples) is controlled by genes elsewhere.\n\nStranger questions would be why do some women have Adam's apples or beards.  Nobody knows.
1144209
psychologically, the nipple represents the breast, and they do not look completely topless unless you can see the nipple. same reason you dont notice a womans breasts as much untill her nipples get hard....you ate from them for a long time as a child, they hold fasination
2744
When a child is conceived, it is firstly a girl. Later in its development it can turn into a boy. So the male nipples are probably a remainder of the girl he used to be when it was an embrio.
91408
Mammillae are standard issue and develop before the sex chromosomes x and y kick in.\n\nAnd that's why men have nipples.
558372
Nice decent women do not like for their nipples to show through except in the bedroom.\n\nIt is a natural effect caused by cool breeze, shirt rubbing against them, and from being horny.
989312
first, human male nipples are not useless, nor are they "vestigial" (more about "use" in a moment)\n\nto answer the latter part of your question...yes!\n\nmales actually can lactate under certain conditions (stress, medicinal/hormonal stimulation, and others); males do have, unbeknown to many, mammary glands\n\nbut male lactation is an unusual, rare event\n\nand human males would not be able to produce the quantities of milk needed to adequately nurse offspring\n\nthe primary purpose of the human male nipple is to serve as an erotic stimulus\n\nthe very first command that god gave to man and woman (adam and eve) was reproduce and fill the earth (ie, have sex and make babies)\n\n(of course the sexual relationship was always and only intended to be addressed within the marriage relationship...on the other hand, neither was it intended to be limited to some simple act of nothing more than making babies; it was also intended for pleasure according to the "song of songs"\n\nin the physically fit male, which men were originally intended to be, the nipples serve to sexually stimulate the female when they gaze at their husbands while working or relaxing; they also serve to sexually stimulate the male when his wife offers manual or oral stimulation\n\nin short, the primary function of male nipples is to serve as an erogenous zone (through visual and/or tactile stimulation)
126709
instinct..man's primal desire for breast...the sucking stage' in psychology.Get turned on big boobs because they are easily seen. But we can still be turned on even on small breast.Remember men are visual. There is rise on blood pressure..heart is pounding.
1087551
It's because human nipples appear during pregnancy in the third or fourth week of development, well before the sex characteristics. So the nipples are there before you become a girl or a boy. But once you become a boy, they don't just fall off.\nNote: Kilroymaster: Please name your source. From what I've read, no male of any kind, human or animal, has ever produced milk.
128418
Every animal comes from a "generic" base model.. the "Y" chromosome chooses to make that base model male.  All body parts translate into some part or another between the two sexes.  So, men AND women therefore have nipples.
3475
Because in the womb, we develop equally until a certain point where our respective genders become more apparent. The period before this is when men grow nipples.\n\nBesides, can you imagine life without your nipples? A bleak world indeed.
168472
They have boobs because they are the ones that give birth.  So she can give the baby milk until it is old enough to eat food.\nThey wear bra's to keep their boobs from sagging too much, because after some years, just like old peoples skin sags, boobs droop down, if they weren't supported for all those years.
47910
actually, I think men were given nipples, so they have something to play with in case they loose their balls
495026
in some cases, men should wear bras.  I've seen some big men out there and they have bigger boobs than me and I'm a girl...it's sad..but true...did you know some men do wear bras? I know one and it's more like a bra to hold the fat in so it doesn't show as well as helping with medical reasons like back problems...