[......Well, he gave Sebastian a kitten. That counts as doing something. Lucifer tried.]
[Anyway. Sebastian shakes his head no:]
Not the only one, ma'am. My young master asked for it not to be made known, as well. [Sebastian is very considerate, you see, of his child master's feelings and wishes.]
As a rule, I tell no lies, [a rule which is only in place because Ciel forbids him from lying, but who's counting...] and yet I realise that keeping this fact about myself hidden can be seen as dishonesty.
[He doesn't sound sorry, exactly, as much as the apology might be implied in his words-- rather, it's more of a matter-of-fact explanation.]