[Yes, he knows what Sebastian's like, and he'll never make the mistake of forgetting it again. Though in this case, he hadn't a choice in remembering just who and what Sebastian is capable of, which if Ciel is to judge of this place, could still happen in the future. How on earth is he to defend against such a thing?
Another thing that he'll have to consider at a later time, especially since they've reached their building. He notices a couple of people by the side of the building chasing a feather, one crashing into the other as they both dive for the feather. Amateurs. He raises an eyebrow when one of them stammers and blushes, and is still watching them when he tells Sebastian:]
I won't allow you to employ such tactics against me in the future. It's despicable, treating your master like common prey. [Turns to stare evenly at Sebastian.] And I doubt I'll forgive you for humiliating me.