First off, how old are you? Second of all, it's your body. If you're 18+ you're able to do whatever you want without a parent's consent. Do you have any other piercings? If so, try to tell them that you know how to take care of piercings so there will be no harm. If not, I would suggest getting an ear piercing of some sort and SHOW them that you're capable to taking care of yourself. I don't see why they won't allow it. It's not like they're going to see it on a daily basis (it's covered by your shirt for the majority of the time). I'm not a rebel, but I would just go out and get pierced without letting my parents know. They just find out later. They were surprised at first, but they didn't shun me too much. Although, each parent is different. So in other words, I would just say, prove to them that you're capable of taking care of yourself. And remind them that you're old enough to make your own decisions and that it's YOUR body, not theirs. If all fails, just wait until you move out. lol.