I friend of mine had both her nipples tattooed a few weeks apart.
She said the 1st one was alright but the 2nd one hurt a lot more and took longer to heal. She stopped wearing bras until they healed and had to wear loose fitting t shirts. She wore a big bandage and padding over each breast.
Cool, nice tats, but I'm not going to consider calling up an old friend and asking her to show pictures of her breasts to strangers on line unless I see some 'interestingly placed' tattoos first