So...at first I was gonna get my nose pierced...?

How bogus is this?! I asked my mom if I could get my nose pierced. She said yes, and that she would take me either Wednesday or Friday. Then we decided on Wednesday. We decided that on Tuesday night. My step-dad convinced me to get my tongue done instead though. They got me SOOO stoked! Then...Wed. morning they said it was a bad idea, they're worried, and don't want me to get it done. I'm FURIOUS! How messed up is that?! What can I do to change their minds ): HELPP!!!