Alcuin could indeed hear Aaron's feelings for Kersen.

He was just blunt about it. "I know you have real feelings for him," he said. "And he seems so lovely, truly. Handsome and kind." Especially for a vampire, kinder than Hannibal. But there was still something about him that reminded Alcuin of some of the better parts of Hannibal, a sort of wisdom that came from so many years of experience.

"I know you're capable of making your own decisions, I just don't want to be responsible for holding you back."