Emma/Ellie
He wants attention. You'll have to navigate the waters to find a way to be stern without caving into his desire to annoy you. You don't have to be nice, you just need to learn how to handle sharing space with him. If he's a little beast, I don't expect or especially want you to just let bad behavior slide. I also believe you'd be a very stabilizing force for him if you manage to earn his respect and friendship. But that will take time.