Originally Posted by
ultravioletlt 
I just need some guidance in how I should respond to someone who is clearly very deep in his addiction.
Yes, this is the problem.
The best guidance I can give is to treat this like a sponsor would. I've seen guys drink on the bus ride home from rehab. I picked up a guy coming home from rehab last year drunk in the airport bar.
The one big difference between you and a sponsor who sees the same thing all the time, is emotional detachment.
This guy's actions affect you, hurt you, betray you, dominate you, and all around drive you crazy. You can't control what he does. You can't control the outcome. All that does is harm yourself.
You can get that same detachment by working the 12 Steps in Al-Anon. you can get to a place where you are OK, content and happy, with or without his drinking and with or without him.
And when a person changes like that, their perception changes. And the actions of other people no longer dominates them.