I came to this party late, but I think you need to talk more before making a final decision. Someone mentioned that it's not about the tattoos, it's about respect, and it's true. So I won't weigh in with my opinions on tattoos or tell you what to do in this situation about getting one or not. I won't say, "Go for it dude! You only live once" or, "Hey, she doesn't want it, don't do it." The best answer is going to come from you telling her what's on your mind and heart, and from her responding with the same - until you both finally say the same answer. Imagine if you tell her, "Honey, I'm glad we talked about this so much and your feelings in this matter are so important to me now that you've communicated them to me that I don't want this tat anymore." Or if she tells you, "Babe, now that I know how deeply you feel about this, I want to go with you to pick out the style of the tat you want."
This is the pattern of negotiation and communication that is respectful and most effective in any long-term relationship, not just marriage.