NEG, it's got to be so hard I know I'd feel the same as you. You are concerned about enabling. I can remember making a list of all the things I did to hide xabf's drinking without even realizing it! A lot of it was to hide it from his family. (because I mistakenly thought at the time that he was just going through a really rough period in his life and that it would certainly calm down at some point so why alarm his family.) When I finally did alert his mom to my concerns she dismissed it. I felt bad then that I had helped hide the extent of his drinking problem. But in the end I realize if she did truly acknowledge it still wouldn't stop him.
I guess my advice to you, to clear your conscious would be to not go out of your way to hide his disease. Nor do you need to announce it to everyone. Unless you were planning an intervention...
But most of all do what is right for YOU and let him handle his disease his own way. ie let him lie and hide it himself.