I’m probably wrong but I could only think of this one https://www.mangago.zone/read-manga/in_my_closet/
oh that might be itttt coz i've read it before although i don't remember. so i have to read it again. thank you!!
No problem! It’s been a while for me too, but reading your description, I distinctly remembered this one did have a scene where the MC came out on stage. I’m just unaware if there are any other idol manwha/manga that had a similar situation ^^; enjoy reading
so a scene that i can remember was that they're an idol group and one member of that group came out during a stage performance (?) and their fans were really supportive. i think before the performance and the coming out happened, there were already speculations that the member was gay (?) i think i can remember the fans having a banner for support too (?) sorry everything is just blurry since i read this a looooong time ago. i thought it was 'hyung, you're my idol' but i just recently finished it and i didn't find that scene