I despise smoking and consider it worse than drugs because smoking can affect other people. You can't get second hand heroin or second hand crack cocaine but you can get second hand smoking.
Can you imagine the smell of her chain-smoker's breath when she's whispering so close to his face?
MC dude should have added the condition she stops smoking. Alas, I fear the author has a female smoking fetish. Worst of all, once she inevitably gets a lung cancer, the MC will simply cure it.