AITA for stealing a tattoo idea from my girlfriend?

I (20M) love tattoos, they’re an amazing source of self expression and I take great care into finding tattoos that I love and truly want so that I’ll be happy with them forever. I have a tattoo currently that’s missing a piece, and I wanted to fill it with some design of the moon. I’ve been searching forever for the right design that I would truly be happy with.

My girlfriend and I have been watching Soul Eater lately, and the design for the moon in that show just really gets me excited when I see it and I think it would be perfect to fill in the spot that I’m missing. The problem is that my girlfriend loves Soul Eater, she’s seen it a million times before and it’s one of her favorite shows, and she’s mentioned on a few occasions before that she wanted that moon tattooed as well.

I brought up to her that I was thinking about getting the moon tattooed but she got very upset with me as she says the show doesn’t have the same meaning to me as it does for her, and that I knew it was her idea to get it so it’s disrespectful for me to “steal” it. She said that it made her mad that I would potentially getting it first when it was her idea in the first place she just can’t afford to get it done. It’s true that the show doesn’t have the same meaning for me as it does for her, I just really like the design. Am I the asshole?

EDIT: Clarification on it meaning something vs not meaning something to me, I have a tattoo that was supposed to include something to involve time and ended up going with a design without it, so since then (about 8-9 months ago maybe) I’ve been dead set on getting a moon related design as a symbol for the passage of time as I’ve always loved the moon. I also wanted a moon as I’m studying aerospace in college and it’s very fitting. This may or may not be relevant to your comment I’ve just seen a few that this might help with understanding. EDIT 2: I'm not getting the moon exactly as it's portrayed in the show either, I have a particular shading style I want and I wanted to add some clouds around it.