Crowley isn’t unkind. Like, in general. He’s just not.
He creates mischief, and he’ll do bad things if he must, but given a choice, he generally chooses the kindest method to do something that he can get away with.
He refuses to kill children. He would rather run than fight. He scares the shit out of the paintballers, sure, but they all get near misses. He lets Aziraphale question the lady at the convent because Aziraphale will be kinder about it. He freezes time for Aziraphale in Paris, rather than come in guns blazing or by hurting anyone. He takes Jesus to see the world- the stories will say he did it to tempt him, but we see Crowley’s face and we know he did it out of compassion, out of a hope that he could save him, somehow, by showing him everything that was available to him. He delivers the antichrist and immediately seeks out an angel to help him undo what he has done, and by raising the child better, not by any unkindness.
And look at the other demons. Hastur tells him about the pastor: ‘i put doubt into his mind’ which implies direct manipulation of mortals. Hastur caused that evil directly. Crowley isn’t like that. Crowley tends to affect the environment, to set up situations, to cause low grade evil that isn’t really any one particular person’s fault and won’t damn anyone on its own. He leaves people the free will to choose to commit the evil or not. His evil is the sort that knocks out the phone network and leaves people the opportunity to either get mad and lash out or shrug and go about their business. His brand of evil is to do his best to give humans a fighting chance to do the right thing, still.
Like he’s just. Kind. Or at least, as best as he can be, considering his job requirements and the role he must play to continue to exist.
And how must it feel, to want to be that kind, while knowing it is against the rules and could get him killed?
And how must it feel to be have found this absolutely perfect angel, and angel who should hate him, who should want him dead, who should try to kill him, himself….. who presents him every opportunity to be kind, and so obviously approves of it, even loves his kindness at every turn?
When all of hell would destroy Crowley for his kindness and when none in heaven recognized it, the one angel he is beside on Earth not only notices but adores it.
And that’s what makes it different, when Aziraphale asks him, with just a look, to clean the coat. That’s the difference- Crowley’s kindness.
Aziraphale cleaning his own coat with a miracle would be an act of selfishness that Aziraphale would remember every time he looked at the coat.
If Crowley does it, that’s an act of kindness. That’s something Aziraphale would want to remember every time he looked at the coat.
And that’s why Crowley does it- because he wants to be kind, and he’s so, so willing to indulge the only creature in any world that has ever noticed or cared.
