Parents aspect to piercings

Hey guys I have a question? How would you feel if your child who was of legal age went and got a small piercing without telling you? I'm 20, I still live with my parents. I went and got a tiny nose piercing, I got the smallest stud they had. My mom is flipping out because I didn't tell her but I'm 20, I paid for it and it's my nose. I was just wondering how you would feel as a parent?