Parents overbearing

I'm 18 almost 19, I have my own job, make my own money, have not borrowed a penny off my parents. I pay rent, I buy my own food, I do everything by myself. I've recently decided I wanted to save up to get a tattoo, once my parents found out about it, they absolutely lost their shit. I can't even get a good reason out of them. They just keep saying I'm gonna ruin my skin and if they see one on me they'll kick me out. I'm very baffled at my own parents. I would legally have a month before I have to leave plus the time before I do get the tattoo to search for another place. I feel iffy about getting a tattoo cause I don't wanna ruin my relationship with my parents, but I shouldn't have to feel bad about something I've wanted for awhile.