Her decision to go, and her preoccupation in leaving the room, had come from the sudden sense that there would be a sort of deception in her voluntarily allowing any further intercourse between herself and Will which she was unable to mention to her husband, and already her errand in seeking Lydgate was a matter of concealment.
There are no more uses of "deception" in the book.
Show samples from other sources
However, like all dangerous deceptions, the lies that clappers tell themselves wear seductive disguises.
Neal Shusterman -- Unwind
Not to know after all these years that deception can hide in plain sight?