I dont think its this one but it has white hair https://www.mangago.me/read-manga/back_to_school/
https://www.mangaupdates.com/series/wcl7oif/fukushuu-ga-tokenai
doesn't look like it's been translated officially or unofficially.
YESSS IT'S THIS ONE OMG I CAN'T BELIEVE IT YOU FOUND IT YOU'RE THE BEST!! But it’s honestly so weird I swear I read an unofficial translation but now it's literally nowhere to be found on the internet. I don't know a word of Japanese and I could've sworn I read it in English on Mangago but it doesn't even exist here or anywhere else How on earth do I know the whole plot if there isn't an scanlation anywhere?!

Hi everyone! I’m trying to find a manga I lost track of. I can't remember the title, but the plot was really interesting.
The Backstory:
It’s about three longtime friends (either childhood friends or met in middle/high school).. Back in school, two of them started dating. Out of jealousy and the fear of being left out, the main character (MC) decided to spread a malicious rumor to expose them.
The Plot:
Years later, the MC enters the workforce (or university?) and crosses paths with his former friends again. Because he feels incredibly guilty about what he did in the past, he agrees to enter a BDSM relationship with them.
Character dynamics:
The White-Haired Friend: He tests the MC with very harsh/intense BDSM acts to see if he is truly sorry, serious, and loyal now.
The Dark-Haired Friend: He acts as the comforter. Whenever the MC is pushed too hard by the white-haired guy, the dark-haired guy consoles him. However, his intentions twist over time because he falls for the MC and starts enjoying the fact that the MC constantly runs to his arms for comfort.
Relationship dynamic: Both the white-haired and dark-haired friends act as the "tops" in the threesome relationship, even though the dark-haired guy is the bottom within his relationship with the white-haired guy, despite looking taller and more masculine.
The Climax & Ending:
Eventually, the MC's earnest efforts pay off, and the white-haired guy finally begins to soften up. However, a misunderstanding occurs when they see the MC being incredibly nice to a co-worker. The white-haired guy feels betrayed all over again. After a heated confrontation and discussing everything openly, all three of them confess their love and officially start dating as a polyamorous trio.
Does anyone happen to know the title of this manga?? Pls ╥﹏╥