Its not really being addicted to the girl, but addicted to the way she makes him feel. He's addicted to the feeling he gets with her.. comparing it to the addiction of nicotine. Later on, she has an epiphany and realizes the cycle and leaves him for good. Hence, "How's it gonna feel when you come back around and see, it's just you and your cigarettes."
Its not really being addicted to the girl, but addicted to the way she makes him feel. He's addicted to the feeling he gets with her.. comparing it to the addiction of nicotine. Later on, she has an epiphany and realizes the cycle and leaves him for good. Hence, "How's it gonna feel when you come back around and see, it's just you and your cigarettes."