You don't. This is the one day at a time part. I don't know either. My wife's been sober for over a year. She could be relapsing right now. I don't think she is, but she could be. That's the life I've chosen for now, but my choice is also one day at a time.
This, in my opinion, is the only reality when you are in a relationship with an alcoholic.
Cyranoak