How can I get my parents to agree to a peircing?

I've been needing a change in my life, something to kickstart my new beginning. I didnt want anything drastic, just something simple to express myself. I've done all the research, I know the risks, and pretty much everything there is to know, and I want to get my tongue peirced. When I brought the idea up with my mother she went ballistic on me and everyting she said was completely irrational. I am smart enough to not peirce it myself, and I am also smart enough to know that if I'm going to do this, I need to go to a proffessional. But as I am only 14, I need parental consent. And as of right now, that seems impossible. Any suggestions?