"No," John agrees, even if he does scoot back a bit to let the other guy in -- not like this is his apartment really anyway. "I'm not. I'm John Constantine." It's all about last name pronunciation, after all.
Constantine does, in fact, sport black hair and may or may not be missing a few inches in height. And while there's no trench coat, he's definitely still got the style of suit and tie. Still, this is how he knows himself, and he doesn't think it's quite fair people keep telling him he's wrong.
He lights a new smoke and then fixes Q with a stare, like maybe he's just got secrets to find.