[He decides to ignore the comment about his apparent desire to not be a demon, it's not the sort of thing he wants to get into with anyone, let alone a priest.]

Must have been passive surveillance, they'd likely only have dug it out once they suspected he'd stopped helping with their plan to end the world.

[There's no hiding the bitterness there, and he doesn't bother. Crowley was never surprised by how eager Heaven was for the end times, but that doesn't mean he can't still be disappointed in them.]