I interpret this as he sees her for who she is, a live wire, who he doesn't want to call "mine." He wants them to be more on the same level, so instead of saying "she's my girl" he wants to be able to say that she's first and foremost his best friend.
I interpret this as he sees her for who she is, a live wire, who he doesn't want to call "mine." He wants them to be more on the same level, so instead of saying "she's my girl" he wants to be able to say that she's first and foremost his best friend.