because of the constiction on blood vessels around the nipplles
because you are exteremely aroused
No. Nipples will harden as a reflex when they are stimulated or cold.
Its cold!
well it depends.... if the females nipples hurt, that means the breasts are maybe sweling for breast milk flow, or they are uncomfotable. Not all pregnate women have their nipples hurt....
Nipples can get sore due to cold weather.
Genetics,,, I once had A girlfriend that had nipples that were undetectable without your eyes.
Your cold, have weird nipples or your turning into a warewolf ;)
more blood comes to the surface of your skin to try and keep your body warm and heat up the muscles around it. this rush of blood causes the nipples to become hard on both men and women.
No your not having a baby
that aint normal
Depending how swollen but it could just be pueberty. Her body or your body might be preparing to begin making breast tissue. My nipples hurt soo bad when I started getting my lady lumps
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Guys LOVE Hard Nipples. It Is Easier For Them To Suck On And Wrap Their Tongues Around!