He had been thinking about this for a while after what Jill told him about your new song which he absolutely can't stop listening to– She said that the song was about him and, he can be slow on these things. He doubts that you sang it for him since you were the one who wanted to keep the relationship a secret in the start. Bruce tried to let it go but he couldn’t.

so now he's here trying to put aside that shyness nobody knows about and ask you about it, “What was your new song about me?"