Lucifer was back in the store, having intended to make it a quick trip to buy a book he'd debated on the day before. Instead, he'd been distracted by the "Ancient Religions" section, and far more time passed than he'd intended.
So when he found himself only steps away from Lady Mary, he wasn't too surprised but clearly she was. And she was trying to avoid him, which he considered allowing, but the urge to apologize in person won over.
He walked over to her, leaving a gap between them and said simply, "Mary."