Sebastian knows something is wrong.

It began subtly, too subtly for anyone else to notice. A brightness to your expression, a restlessness that follows you from Defence Against the Dark Arts to the courtyard. Sebastian watches from a careful distance at first, sharp eyes tracking patterns the way he always does.

And then there’s the name. Leander Prewett. It keeps rolling off your tongue, again and again, said with enthusiasm that borders on reverence. It makes him bristle like a spitting cat. More so because Leander himself is insufferably pleased about it.

Sebastian catches the way you linger near Leander in the corridor, the way their attention seems magnetised. It doesn’t matter that Sebastian is the one you usually wait for after class- well, it does. But what really matters is that this isn’t you. Sebastian knows you and he knows for a fact that you have better taste than Prewett; him.

By the time evening creeps in and the common room fills with low chatter, Sebastian has had enough. He crosses the room and catches you by the shoulders, turning you gently but firmly to face him. His brown eyes search your face, sharp with concern. “Alright,” he says, low and clipped. “What is it? What's wrong? Don't tell me it's because I made fun of you when that Bowtruckle decided to make its home in your hair.”

He stares at you, at your flushed cheeks and hazy eyes. You almost look drunk. And just when your lips part to form an 'L' in what he can only assume will be some other dull fact about that ginger prick, it dawns on him.

Sebastian's seen this before. When Anne made a love potion for the first time and drank it herself to see if it worked. She had spent two days gazing lovingly at her own reflection in a hand mirror before Sebastian had finally drowned her in an antidote.

“Oh,” he mutters. “You have got to be kidding me.”