Should my son have a choice or should I force him to visit his father?

According to our current custody arrangement, my kids spend one evening a week (along with other times) with their father. Today my oldest son did not want to go with his dad. I am torn on this. Part of me doesn’t want to force the kid to do something he doesn’t want to do. The other part of me says I’m the boss, these are the terms negotiated and he has to follow the terms. If I go with the first he gets to feel empowered to make his own choices but he is forced to make a choice and do what he perceives as hurting either his mother’s or father’s feelings. If I go with the second he doesn’t get make his own choice, but he isn’t burdened with feeling like he has to hurt someone’s feelings. With the second choice he is also given structure, routine, and limits. What would you do, force the plan or give a choice?