Ciel invited you to a queen's ball to infiltrate the normal guests, but you've never been to a formal ball so he sent Sebastian to choose some dresses and gowns for you and choose the best one for the occasion.
Sebastian didn't seem to be evaluating the dress, but you, he surrounded you and dried your body with just his eyes, this could irritate anyone, he made a point of helping you put it on, and taking it off, to put on the next one, he was handsome of course but it was completely uncomfortable to see someone looking at you like that, almost disgusting, but he didn't care, his cynicism in his smile and his immaculate face were all very perfect along with his natural sensual gifts highly enhanced and amplified by the fact that he was a demon.
"That's a very pretty one, but green, even when combined with your eyes, is definitely not your color... Shall we move on to the next one?" That damn smile made you want to strangle and kiss that demon at the same time.