"No, that's the only boring book."

The one that Istredd has already practically sanctified. And! Maybe it is interesting! But they both know it likely isn't. Its meaning comes through in other ways that Lucifer will not acknowledge despite being the one that sold a firecracker enchantment and went to Nott when he had been adamantly avoiding it since their last trip and bought the dumb, no-nonsense, likely-very-boring book.

So.

"You'd be the first," to say that.