[Very intense. Sebastian sounds so passionate and upset. That, or he just sounds sluggish.]
Oh, I could not... I could not tell you. It is a secret, you see. [Because if he told her he'd have to own up to being a demon, and he can't do that. ...This would normally be a much more clever evasion, okay. He tried.]
He would likely tell if asked, though... seeing as he cannot keep anyone's secrets.