Bite my tongue means never say your feelings or reveal the truth.

To the comment below, since you are best friends with her why not tell her the truth. If you are really the best of friends and she doesn't feel the same accept it. Who knows even if she has a crush she is just testing you if you will reveal your feelings to her or you are really her best friend for life. You are lucky to have a best friend. If feelings are mutual, good for both of you. If not, hope she will still like you to be her best friend. If she will avoid you or be not your best friend anymore, it means she was never really your best friend.

Lyric Interpretation Guest