When my son was a teenager, and lots of his friends were having tattoos. my main comments to him were about safety and commonsense. I told him that if he considered having a tattoo, most importantly to go to a qualified person, using safe and proper equipment. The other was a suggestion that he might think where on his body he might have one, and as he did not know at that time where or what kind of work he might do in the future, that whatever he had, to have it where it would be covered by a long sleeved shirt, in the beginning. He did eventually have a tattoo but had thought about what I said, which made sense to him then. In later years he has had more tattoos , and fortunately hasnt had any bad reaction to them.
Personally as a needle phobic , it is not something I would ever choose to do. Each to their own, I feel, but have advised people to avoid putting names on, as who knows what may change in life. Then there is also the ones that are supposed to be funny, which I really think are stupid, such as the line round the neck and cut here written on them. That joke will only be funny for a very short time and then they will have to cope with it or cover it for years. But in the end , as adults we are responsible for our own choices, and we may like or dislike what people wear or what colour they have their hair, or different styles of beards . We are entitled to our opinions , but do not feel it is up to us to make any comments on other peoples choices unless they ask for them. Live and let live on such things is my view.