A book where the main love interest doesn’t get the main character in the end—someone else does. (Could also be that the main character doesn’t get their love interest in the end, someone else does or any variation on this)

“I'm not your problem anymore
So who am I offending now?
You were my crown
Now I'm in exile, seein' you out
I think I've seen this film before
So I'm leavin' out the side door”