12 years sober, wow. My AH hasn't been able to get 6 days sober.
I can understand your concerns... you've been there, done that and don't want to do it again, especially with children. And his dishonesty about his drinking leaves you unable to know what to believe now. You have every reason to be frustrated with the situation... On the other hand, you have 12 good years and that's a lot of reason to have hope that this relapse of his can be a thing of the past before long.
Unfortunately, I seem to have misplaced my crystal ball so I don't know what the future holds for myself, let alone anyone else. All we can do is keep trying to be the people we want to be and living the lives we want to live while we wait to see what choices the A is going to make. Making plans for how to deal with whatever choices my AH makes helps keep me halfway sane. But mostly, I'm just trying to live my life well while I wait to see if my AH will get healthy.
Welcome to SR and good luck.