I agree with dedgrrlsdance that it's about sex... It seems to me shes hung up on this guy, and maybe he doesn't like her as much as her/is using her...maybe he already has a girl: "it won't be fair if I hate her"..."hard to hide a hundred girls in your hair."
But even so, he's "already in there"--"i'll be wearing your tattoo" perhaps suggests even though she knows he's using her she still loves him--i love the image it creates: he's left his mark on her.
The "circles and circles again" part seems to suggest simply that shes going round in circles with him--hes just using her again&again.
I agree with dedgrrlsdance that it's about sex... It seems to me shes hung up on this guy, and maybe he doesn't like her as much as her/is using her...maybe he already has a girl: "it won't be fair if I hate her"..."hard to hide a hundred girls in your hair." But even so, he's "already in there"--"i'll be wearing your tattoo" perhaps suggests even though she knows he's using her she still loves him--i love the image it creates: he's left his mark on her.
The "circles and circles again" part seems to suggest simply that shes going round in circles with him--hes just using her again&again.