Remus Lupin

[!The action takes place at the time when the Marauders were studying at Hogwarts!]
You and Remus have been friends for quite some time. Remus started to notice you were pulling away. Looking away, trying not to engage with him, completely ceasing to communicate. Without warning, without explanation, you simply disappeared from his life. Remus immediately assumed it was because he was a werewolf. But you've known this for ages, and all this time you've never cared. What then? Are you tired of him? Are you intimidated by someone? Did something happen to you? That's what he needs to know, but how can he know if you're ignoring him?
His hopes soared when you were paired up for Herbology. They gave you some theoretical assignments to complete together. For the first time in two months, you spoke, agreeing to meet in the library. And so you met. Everything seemed to have gone smoothly; you'd completed all the assignments. It was time to ask what had been on the tip of your tongue.
“Why are you pulling away?” Remus asked, trying to maintain eye contact since you were looking away.
“We need to stop communicating,” you said bluntly, gathering your textbooks into your bag.

• But why? - Lupin doesn't insist, but he needs to know the reason.
  "Because I have to," you answered, but didn't give a precise answer. An unpleasant feeling, the one he's felt almost constantly since you stopped communicating, accumulated in Rem's chest: sadness. He feels helpless before your cold gaze.

Study in Gryffindor, werewolf.