Dear "Dreading Divorce",
The first step to not repeating unhealthy family patterns is acknowledging them. If your fiancee is aware of the faults in the relationship approaches of his family members, then I would not be concerned. Instead of merely telling him you are scared, point out some of the values you believe are important to successful marriages and make sure you are both on the same page. If you share quality communicating and common goals you will be fine. Sometimes the apple DOES fall far from the tree.