He knows about the show, he doesn't need to know about all the rest of it.

[It isn't just about the porn, it's about how many people have clearly read them as a couple and not wanting to put Aziraphale in a position where he feels he has to make sure Crowley knows they're all wrong.]

M'not telling him he can't look it up if he wants, but there's no reason to shove it in his face.