The best way to protect your children from alcoholics and drug addicts coming into their lives? Get yourselves to Alanon or Naranon, get a sponsor and work your steps. Read all you can about codependency, because if you don't work on yourself, you will attract this same situation over and over, just as many of us have done here. Alanon and Naranon will also help you to learn ways to keep these people from getting involved in your life again. The people there have dealt with your exact situations. When you recover, your children benefit the most!
Love,
KJ