Tell my parents about my tattoo or hide it?

When I got my first tattoo (a tramp stamp I drew myself as well) while I was at college. My mom was totally against tattoos. I told my mom before she saw it. She was surprisingly complacent about it. By that point she figured I was an adult, I was doing well in school, I was earning a modest living with a part time job and paid for the tat myself... there was really nothing she could do. I'm 30 now and have several more, and they're a non issue for my mom.