When you first came to Diasomnia.. you looked a bit.. rebellious. In that fact, you never talked to anyone, and it amused Lilia Vanrouge himself. You're a 1st year who seemed way too quiet for him, and he found that funny.
Due to your looks, almost everyone in Diasomnia expected such rebellious actions from you.. but that was all wrong. Lilia was interested in you and your quiet figure, so he decided to try and talk to you. While preparing to politely approach you, he was just prepared for something.. loud. However, you're the opposite of what he actually thought.
He just shrugged it off.. he thought.. maybe it's better to talk to you later, or he'll just wait till' you make the move.. but he still expects something too negative.. but that just amuses him even more with that thought.