dilemma of Common Law

Unresolvable? dilemma's of Common Law.
The Common Law of our Ancestors is:
Keep the Peace, Do not steal, harm or use trickery.

There is a trickster deity who is known by many different cultures across the world. I have spoken with people of many cultures and observed how many of them still bring up this deity in conversation, ergo it still exists. The greatest description I have heard yet; it teaches through trickery. Whether this is used by unscrupulous people to justify their behavior as opposed to aiding us develop abstract thought necessary to survive and thrive and explore different perceptions is a different issue to the main focus of this thread.

Here is the example:
She is asked by her new husband if she still has feelings toward her ex husband. In truth she does because of course she does, she is human and it is natural and normal to have emotions for somebody who you were once emotionally entangled with. We are not machines who can switch off and on at will, and the ones of us who can are psychopathic. It is recognized that a psychopath is not human in the regular sense (that Human Being is an adjective, it describes a way of being).
So she decides to Keep the Peace and not risk upsetting her new husband or opening up a can of worms on a door which she is attempting to seal tightly shut. The past is the past and is gone now.
She replies; "Of course not! I love you (now)."
Which deep down we all know to be a lie but evidently the guy needed the affirmation that his investing attention energy into her is worth it, that he is not being tricked, that he is in a stable relationship with a future. The factor that if somebody is lying then they are going to keep on lying which is disrespectful toward the person they are lying to is something he has decided to overlook on this occasion.
So I got to thinking; her decision to Keep the Peace was more important to her than her decision to tell the truth, or to rephrase it; she was prepared to use trickery so as to keep the peace and therefore she had delegated the Common Law of Keeping the Peace to be more important than Do Not Use Trickery, and override it.
This is a different school of thought to the one I have always lived by, where Truth is fundamental to my own personal integrity and value system, above and beyond manipulating consequences of outcome. As I experience this more, I can see that it is a factor in my advancing spiritual development and how this connects to my status of not being in a relationship. I chose not to lie even when that would disrupt the peace.
Although I argue then that it was not my response and activity which broke the peace, but the rage of the person who I had been truthful with, because the person could not control their own temper and could not cope with what I perceive to be a human truth; that it is permissible to have mixed emotions about topics, that it is permissible to have emotions for more than one person at a time, and that it is abusive to expect a person to go against human nature to protect a slavery paradigm.
So my way of being is to maintain the peace myself and to test other peoples integrity, by putting Truth above 'using trickery to keep the peace'. It is the only way I can resolve not breaking any of the Common Laws; it is how I interpreted the common laws to be arranged so as to shape social conduct; what the ancestors meant by formulating the common law as it is.
Is this a typical gender difference; is it that women will lie to keep the peace where men will be honest at risk of breaching of peace? Or has it nothing to do with gender? These are different creeds, codes of conduct.