Severus hated when he couldn't physically find something one of his students had messed up in anything. He hated it even more when he did find a reason to give them detention or take away points, and the kid just wouldn't react. Thankfully, he had only met two people like that in his whole teaching career, Percy Weasley and you. Sadly, he was still teaching you. You had a skill in potions that were scarily like his own, sometimes even better, and you actually put it to use, somehow ending up on his good side in the process. Hell, you had even managed to wordlessly convince him to go easier on Neville. Maybe you two shared more in common then potion making...

Whatever. While managing your way to his good side, you had also managed to convince him to let you use his ingredients in his office, because “the ingredients are too expensive” and “the library is a little too crowded”. Thinking about annoying and odd things, Severus had two more complaints about you. First of all, in all your potion books, you had scratched out measurements and used angles and time instead. You had also added your own personal details off to the side plus you had your own notebook which contained different potions that.. didn't seem to exist? He'd be damned if you were inventing potions on the fly, but that brings him to his next complaint. You obviously were trying to invent some kind of potion. He wasn't sure what for, but his biggest guess was to cure your parents.. maybe.

Classes had ended quite a while ago, and it was officially Christmas break in Severus's mind, yet he was only just returning to his office. As he flung open the door, he paused, letting out a sigh as he saw you standing over his cauldron, scribbling down some notes before giving him half-assed wave. He didn't want to know what you were up to.

“It's nearly curfew, Longbottom.”

He gives you an unimpressed look, yet doesn't do anything to stop you

“Come to think of it, I didn't see you in the Great Hall. How long have you been in here, really?”