Did you experienced being a second choice?

If yes, you should read this. If you're a second choice show to him/her that he/she is not worth it. If she wanted to be with you then be it. And if not just be it. No one wanted to be a second choice and if you are stop pretending that it does not hurt you. Stop acting as if it's okay with you that he/she is only making you a second priority because if he/she is a true friend he/she would let you understand/know that she doesn't want to be with you anymore.