Charles has always left Edwin little notes slipped between the pages of his favorite books, in his science equipment, places he knows Edwin loves. Just silly things—post its that say “hi Edwin :)”. doodles of Edwin with his nose stuck in a book. reminders to stock up on wolfsbane. but.
Then, post canon, Edwin tentatively starts dating people. And it’s ridiculous, because Edwin’s right there, all the time, but Charles..misses him a bit. And his heads a mess, and he can’t sort out what the hell he’s feeling most of the time, and whenever he tries to say any of it out loud it comes out rubbish.
So. He writes down some of the shit he can’t say right, and because he’s a coward, hides them so he doesn’t have to see Edwin’s face when he reads them.
then Edwin starts writing back.
Neat lilac blue little envelopes appear in Charles coat pockets. In his bag. Once, in his shoe? Some nights, Edwin will clear his throat and mention something from a letter, offhand, like they’re just picking up conversation, and Charles can pretend they are. That they always have talked about the basement, the belt, the nameless fear that chokes him every time Edwin walks out the door with someone else on his arm.
Sometimes he can’t. The words get stuck in his throat. Edwin’s not mad, he’s maddeningly, stubbornly kind about it, which is worse.
Some nights they trade. A secret for a secret. Charles learns about the novels Edwin used to hide under his mattress, about all the lonely years before Charles got there. About Simon.
Meanwhile, Edwin is losing his mind, because Charles has accidentally stumbled onto what was a fucking courting ritual in his time. Love letters were something engaged couples treasured for years, kept and reread over and over. (Edwin does. keep them in a special box, will take one out and trace the words, tuck it in his breast pocket for courage).
Edwin would rather have to reattach a limb again than lose Charles trust, all the dark and beautiful things he shares with Edwin only. He knows—knows Charles doesn’t mean to make him fall more in love with him.