Why this insistence that things should matter to me?
[He may have been a brat, but he remembers the face Lucifer made when Sebastian spoke of his own aesthetics as a vain attempt to have something matter. Not to mention the, ah, cat challenge, shall we say.]
I do not see why it bothers you so.
[This is all in a mildly confused, curious tone - not in the least annoyed or sarcastic. Like he said, he's not Lucifer's demon? Well, aside from when he conveniently was because it made for good guilt-tripping material.]