I think they would grumble at each other quite often lol! Ciel would really be annoyed with Leona and it would be difficult for him to understand him, unlike him, he is ready to work hard on himself. Leona would have been interested in Ciel's purposefulness from some point of view and I think he would have been one of the first to realize that Ciel is really a treacherous child in fact 💘💘💘