Okay, I'll field this newly vacated nodeshell.
A nipple ring is, quite obviously, a ring for your nipple(s). To be more specific, a ring put through the nipple itself in the grand tradition of body piercing. The 'ring' may actually be not a ring at all, as it is also common to have barbels put through this sensetive area as well, though the rings seem to be more popular.
In fact, the 'nipple' part could also be debated on the grounds that a 'correct' nipple piercing will usually be put through the base of the nipples' protrudence, through the areola. This, I have been told, is safer because it minimizes the possibility of it tearing out. Ouch.
Though I lack them (nipple rings, I mean. I have Nipples. All 3 of them), I have also been told by a friend who has them that there are a few rules to follow:
- Do not yank someone around by their nipple piercings. Sure, it may look fun, but it's not the toughest or strongest area of the the body. This also goes along with 'don't attempt to lift cars with your nipple rings'.
- Wear a sweater when it gets cold. Metal (and to a lesser extent, Plastic) conducts heat very well. It also conducts cold -- as in "in brings the cold right into your chest and turns those nipples you value so much into pierced blocks of ice".
- If they are made of a ferous metal (ie Steel), take them out when going through an airport. It saves a lot of embarassing explaination. (Yes, I *have* been told by no less than 3 people that they don't really set off airport metal detectors. You don't need to tell me again. Honest.)
- Above goes well with science labs, too. Could you imagine how humiliatating it must have been to have to explain to the paramedics that your chest is stuck to the super-gauss electromagnet?