To answer the breastfeeding question and reference, breastfeeding should never "hurt". Mildly discomforting at the beginnning, but if there is lingering pain after the first minute of a feeding, then there's a latch-on problem. And nipples never toughen up. That's an old wives tale. It was assumed that they toughened up since the feedings became less and less uncomfortable. The reason for that was that the baby and mother adjusted to each other and the latch self-corrected.
As for the milk "squirting out like a sprinkler", if the piercing went through a milk duct, the milk could very well come out the piercing. On the other hand, if there was significant nerve trauma to the nipple, it could interfere with the "let down" process and could decrease the milk production. I've counseled women who had their nipples pierced that went on to nurse very successfully, and others that weren't so lucky. So if any woman wants to nurse in the future, give nipple piercings a second though before proceeding.
Hope this doesn't sound too clinical, just a pitfall of my employment.
