I absolutely second Mike here. He will do what he does. So you do what you do; continue to be authentic to yourself and then to your girls. They will appreciate it when they are older.
I also think there is nothing wrong with feeling some sweet vindication in his screw-ups. So what if you took some "joy" in his Father's Day debacle anyway? Here's a good response to that crap: "perhaps" with a wicked grin. You neither confirm nor deny.
Keep feeding him the proverbial rope, WTBH. He's tying his own noose right now - its only a matter of time before he is dangling from it.
And lastly, I must steal the line used in a recent thread (and my apologies to who said it because I don't remember now, but it was pure brilliance!). Don't take on a diagnosis from an alcoholic.