Years ago, I wanted my girlfriend to get her belly button pierced. While we were at the tattoo/piercing parlor, she said she would ONLY do it, if I got something pierced. Thanks to liquid courage, I finally agreed to what I thought was the least invasive piercing and got my left nipple pierced. The next morning, I rolled over and had a piercing (no pun intended) pain. It was only then that I realized what I had done, lol. Oddly, before it was pierced my nipples had no real sensation, but after, if my left nipple was played with, I'd get instantly hard. I no longer have the piercing, but my left nipple remains super sensitive, and I love it. Sometimes when I'm jerking, I'll pinch it or even put a clothes pin on it...definitely increases the intensity of my orgasm.