I've heard that starting or doing business with a family member or relative, can create many legal problems as well as relationship issues. For example, a father letting out a house to his son could be problematic if the son chooses not to pay the rental costs. This ultimately means an eviction will occur sooner rather than later. Another scenario would be a family restaurant, where the father is the owner and the son is a general manager. What happens when they both get into an argument, on a personal level? This is why I think business and family don't mix.
Share your thoughts and personal experiences below.