Don't you like your good old vassal Franz? Then fear not. You are now able to make everybody laugh about him. All you have to do is make him court jester. Making him court jester gives him a negative opinion modifier towards you. This coud be useful if you want somebody to revolt to take away their titles. With the latest patch, it might force him into joining a faction, and you would have to fight a whole faction rather then a single count or duke.