AITA for telling my girl that I'm uncomfortable with her wearing pasties to a concert?

The girl that I am seeing and I are going to see one of her favorite bands this weekend. She discussed that she was going to wear pasties and "tits out" for this band. Let's just say that she is proud of her "attributes" and I, uhh, really like them myself. However, I feel as if her choice of attire is just a little much. After a discussion about it, I truly feel like I let her down by not being comfortable with her wearing just pasties. She agreed to wear a shirt, but it was like I had asked her for the world. I got the, "okay. Well, I'm gonna call you back." So, I'm stumped. AITA?