This reminds me of the following passage from We Need to Talk About Kevin by Lionel Shriver:

But keeping secrets is a discipline. I never use to think of myself as a good liar, but after having had some practice I had adopted the prevaricator's credo that one doesn't so much fabricate a lie as marry it. A successful lie cannot be brought into this world and capriciously abandoned; like any committed relationship it must be maintained, and with far more devotion than the truth, which carries on being carelessly true without any help. By contrast, my lie needed me as much as I needed it, and so demanded the constancy of wedlock: Till death do us part.