One easy way is to let your son to be responsible for planning 1 weekend activity, and let your hubby for another one. Let them think of something for the whole family to do. You can assist them to do the planning and research, but you must let them make the decision. After the weekend, ask them what do they think about the activity... although the activity may not be well-planned, but they will feel that they are involved in the whole family decision making process and during the course, this improves the communications between the family members as each of them think for the others and talk to the others.