It means that he does not tell the truth and should not be trusted.
Firstly, how do you know he's lying. Secondly, why are you wondering about his ex. If he is still talking to her and lying about it, I would leave before it gets worse.
If you are bringing it up, I would stop if I were you as it just causes you stress. Be happy with you. Acknowledge what you have as a person instead of wondering about what someone else did.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.