Help on convincing my parents to let me get a belly button ring?

im 16, and going to be a jr in highschool. I have wanted one for awhile now...but my parents are so against it. they wont even consider it or listen to my reasoning. i make good grades, i am involved in student council, mock trail, NHS, all that stuff.... and i wouldnt go around whereing tube tops and stuff... i just think they are really cute. and the thing is i could take it out and stop wearing it if at some point in my life i no longer wanted one.... help??