Honey, reading your past posts and I have a question.
Has he ever owned or taken complete responsibility for anything he has done or that has happened between you?
From what I have read, he turns it all round on to you or some other person or bad luck or whatever, but it is never him, his behavior, his drinking etc.
Now mum sticks her bib in, and it is you who she blames for her son's drinking and behavior, even when it is clear he has had problems since long before you were on the scene. No wonder he won't accept his part in anything, as I guess mum has played this "it aint your fault" recording in his ears for a long time.
You know what is real, and now you see that he is not the "non drinker" he said he was, so where do you go from here?
How many times will you put up with his in and out actions?
It must be like living with a revolving door for you.
Put yourself first now, and your kids have next priority. As for him, well if he walks out again, let him know he can walk to China if he wants, because you have better things to do than waste time on him anymore.
As for dear old mum, well just feel sorry for her and ignore her because you are in the real world and God knows what fairytale she is living in.
God bless