Your inner voice was trying to tell him something, more than likely. Though those two simple words were definitely not expected, especially after he had an idea of what would soon occur for him. Thus after blinking for a brief moment in surprise, she let a single amused sound to escape before placing the cup down.

"...You are welcome, Narukami-kun."

It was getting late, so after spending just a brief more time for discussion, she disappeared in the very fog that made up the illusion of her appearance. In fact, it may just make him wonder if she was even here to begin with. Spoilers: She had been. She was just damn good at teleporting and slight of hand.