If he wont go to aa or continues to drink then its more likely that you will drink if you are around him. If he chooses to drink then what CAN you do ? Nothing and you know that.The very best and probably only thing you can do is FOR you. Take care of your sobriaty,be an example to follow and if/when he asks then show him how you do it. gl
I would be cautious of that. It seems like you are hesitant about it to begin with. Maybe you should suggest he go to AA.