She understood.
She didn't like it, but she understood.
You could even go as far as to say she hated it- them. But, nonetheless, she understood.
She understood what it was like to have a compulsion, a desperate, all consuming need. It doesn't even provide pleasure anymore, just the release you can't live without.
And, so, when the redhead would quietly pick up his jacket and walk to the door, she wouldn't say a thing.
And when he would come home and walk straight into the bathroom, without speaking a word to her, pretending he didn't smell like booze, cheap perfume, and sex, she would listen to the shower and smile and nestle deeper into the covers so that, when he opened the door, he would see her grinning at him from the piles of pillows and blankets and he would drop his towel on the floor and crawl beneath the covers with her and he would smile that smile.
Her favorite smile. The one that said that he didn't want to crawl under the covers with anyone but her.
They may be his drug. But she was his rehab.