Curiosity has already been quite sufficiently punished, I should think, both for humanity and for a ...certain set of occult beings.

Though, I also believe you need not feel obligated to reward him for his persistence.
After all, persistence is not reason enough to get what one wants when it involves the freedoms and comfort of another.

This is not some moral quandary for an angel to weigh in on. This is really quite personal to you, and as such, I think you ought to do exactly what you feel is most right and comfortable for you--regardless of Crowley.

Sorry, darling. [You see those wiles, you thwart.]