Your not the first one to post this. Many people early in recovery do cheat with people in the program because they are not working the steps to begin with and are looking for something to replace the drugs and or alcohol. I wouldnt blame it on AA/NA though. It happens just as much in rehab too. If someone is going to have an affair, they will do it with or without 12 step meetings. If they are faithful and can be trusted to begin with, it shouldnt matter. I wouldnt waste my time with someone I couldnt trust.