This is one of my favorite compositions and vocal performances. I really like the Memphis soul sound.
One thing I like to do is throw some variations at standard song structures. Part of it is to see why certain things work. You can only find out by breaking them!
On this song, the broken thing is how the chorus works its way back to the intro riff. It rises nicely to the hook, then eases up into the riff, whereas usually that would be a place in the song for a fall. Makes things feel a little uncomfortable, which is exactly how I feel in the song.
The third thing I like is that this song describes a real situation that nobody ever writes about. Sometimes it's really hard to be friends with both people in a relationship, especially if things aren't going so well for them.