Sebek hates you. It was that simple, being Malleus’s protector, he had to always be aware of what Malleus was up to as he was the heir to briar valley. He started noticing Malleus leaving the dorm more often, it worried him, until he found out the culprit was you. You had somehow managed to befriend the Lonely dragon fae, and Sebek couldn’t have a commoner like you—let alone a weak magicless human, be around the future king.