Responses
It’s actually straight shoujo:
http://www.mangago.zone/read-manga/suki_ni_naranai_yo_senpai/
AHHHH THANK YOU.. i had a feeling that might be the case but i could only remember details about the ML not the MC
i think it was yaoi but it might’ve been shonen ai, MC saw an amazing painting at a highschool (it might have been university, i’m not sure) open house so he decides to go to that school. as a first year he joins the art club, he likes everyone except for one senpai who was a total womanizer and hooked up with girls in abandoned classrooms. eventually he realizes that the womanizer senpai was the one who made the painting he liked so much , and he didn’t recognize him because of his glasses. i’m pretty sure the senpai has long-ish dark hair?
ALSO this part i’m less sure of so it might be from a different manga but: the senpai used to have a relationship with the teacher who was in charge of the art club until she got engaged and quit.
it might be a manhwa/webtoon instead of a manga?