It seems that GF has turned crazy, and the only way to bring her back to her normal sense is if she were to be defeated by you and BF in a rhythm battle, something you will now do on two awesome songs:
Get your GF back by defeating her in a rap battle!
As the song proceeds, when your turn comes, arrow symbols are going to match above BF’s head, and, when they do, you need to press the same arrow keys to hit notes, something you have to do until the song ends to win it.
Be careful not to miss pressing the keys too many times in a row, since that will lead to your loss and having to start again from scratch, something we wish for none of you. Good luck!