Those who rationalize sin set themselves up to sin more easily.
Also a half-truth is a lie if it is told as the whole truth.
Read: Genesis 20:11-12
11 Abraham replied, “I thought, ‘This is a godless place. They
will want my wife and will kill me to get her.’ 12 And she really
is my sister, for we both have the same father, but different mothers.
And I married her.