Unfortunately for Lilia, it seems this little demon didn't know to follow the teachings that others did, that Lilia had interacted with in the past. He half expects Diamond to bring out his pen and threaten him - it's just how their kinds worked, isolating from each other as much as possible... and, when it wasn't, fighting. Of course, there could be some kinder demons and kinder fae, but Lilia wasn't about to let his guard down.

His red eyes narrow briefly at Diamond, an easy grin coming to his face to match that troublesome smile. Resting both of his arms onto the table, Lilia leans towards the other boy, allowing any tension that might've worked its way up his spine to vanish away in an instant.

Not that it wasn't visible, for a moment.

"And I, you." Lilia replies easily, tilting his head back slightly, to size him up. "Do you? Hate me, that is."

If he did decide to cause trouble, Lilia's confident enough in his physical prowess to take him down before he even manages to cast a single spell.
... Maybe.