it was definitely a BL, don't remember the name tho
This sounds so much like an arc in No Home!
https://www.mangago.zone/read-manga/homeless/ the Field Trip, Haejoon Goh arc
Yes, that's it !!!! Thank you so much, I feel better, it bothered me so much not remembering
The begining of the arc is chapter 115, thanks again
So I think it was a bl, but maybe not, there is just 1 scene that just popped in my mind :
mc is (I think) shy/introvert and his/her class is travelling, there is this guy that is very outgoing that tries to speak to him and basically include him in his group of friend. But mc had already accepted to sit with another guy who seems like a loner. This guy talk sh*t about the popular guy to mc, but he is actually the *ss, like there is a moment he says mc to wait him I think but he leaves him alone to have fun with his friend. Then the popular guy asks Mc if he wants to hang out with him and his friend, and mc says ok. But then when he sees him, the loner *sshole has the audacity to accuse mc of going with others even though HE left him to go with his friends. It ends with popular guy roasting *sshole and mc becomes friend with popular guy and his group of friend who are good people
It was not at all the main part of the story, but it just came back to me, does it ring a bell for anyone ?