Charles, admittedly, doesn't really know how to have fun-- he's the byproduct of strict parenting, studies and the inability to do much else even if he were so inclined to. He is, however, also a sap and willing to go along with Raven on whatever silly adventure she has in mind. So once they reach the fair he drags her along through the booth when the ticket taker isn't looking, ducking through a crowd and then heading inward to get them out of sight before he notices.