It's about a physical relationship that isn't and won't be going anywhere. She knows this. However, she keeps trying fruitlessly to get anything out of him and turn it into an actual relationship. He is only with her to have a physical body to use when he needs one. So she tries to get her own satisfaction and revenge on him by pretending she doesn't care. She's trying to show him that she is using him just for physical relief too. Except she isn't. And she feels awful for pretending to be as cold and hard as him, even though it would make things easier. She keeps going on this turbulent roller coaster. She's living the fantasy of being with him only to crash when she realizes he'll just move on when he finds his "star". But she is staying around and keeping her claws in him in hopes of finally landing the part of his heart. After all, what other girl would want to play the supporting role with her around?
It's about a physical relationship that isn't and won't be going anywhere. She knows this. However, she keeps trying fruitlessly to get anything out of him and turn it into an actual relationship. He is only with her to have a physical body to use when he needs one. So she tries to get her own satisfaction and revenge on him by pretending she doesn't care. She's trying to show him that she is using him just for physical relief too. Except she isn't. And she feels awful for pretending to be as cold and hard as him, even though it would make things easier. She keeps going on this turbulent roller coaster. She's living the fantasy of being with him only to crash when she realizes he'll just move on when he finds his "star". But she is staying around and keeping her claws in him in hopes of finally landing the part of his heart. After all, what other girl would want to play the supporting role with her around?