Piercings along with tattoos from my understanding are accepted among SS. Maxine for instance wrote about getting a tattoo of her GD's sigil. That said, I personally don't agree with taking these things to extremes, such as septum piercings or the ones that leave gaping holes in your ears. This is self-mutilation and a sign of mental health problems.
It's well established that piercings were used by Egyptian Pharaohs as a symbol of status, and tattoos as far as I know were also used in their culture. In ancient Rome, tattoos were used to mark criminals. This is largely how they garnered an air of rebellion. Consider how the Yakuza made piercings and tattoos a very taboo idea in Japan. Many public places there will not allow for them; including schools, swimming pools and shrines.
From what I can tell the Roman empire (i.e the Jesuits) made tattoos into a negative thing.
Keep in mind also that piercings and tattoos today are still considered taboo depending on what job you're in. Lawyers for example often cannot war piercings and they have to cover their tattoos. That said, they are generally more accepted than they were years ago.
I'd recommend meditating on this and contacting your GD for better guidance.
