Welcome to Gambling Therapy. You are in the right place and among those who understand.  
Nothing you have said surprises me.
Knowledge of the addiction to gamble will give you power over it. Lack of remorse and lies are symptomatic of the addiction.  
I know only too well how much you want to convince him that he is taking the wrong path and that his addiction will only bring him misery and failure.  
It is late here for me but I wanted to let you know your post has been read and that I will support you for as long as you want me to.   I will write tomorrow at greater length and hopefully cast some light for you into the dark corners of your son’s addiction.
Well done on starting your thread – the first post is the hardest.  
If you should read this before I get a chance to write again perhaps you could tell me how your son dealt with his addiction when he stopped before.   Is he in a lot of debt?
You have spoken as couple in your post which is great.   The addiction to gamble is divisive and the best thing for your son is your unity on all matters that relate to his addiction.  You are not to blame for your son’s addiction and your son did not ask for it or want it either.  
You might like to have a look at our Friends and Family topic forum which is below this forum.   In it we focus on specific issues and there may be things there for you that will support you.  Please join in on any of the issues – it helps me know the things that are uppermost in your minds, although given time I hope to support you with all of your concerns.  
 I will write again tomorrow