it's a bl manhwa. The main character is a pushover that got bullied in highschool.
one of the bully felt pity for him and they got close. eventually, they fell in love.
the bully is not a hardcore one. he's just a bystander. I'm not sure if he's the male lead or not.
I remember one scene where they kissed in an empty classroom and one of their classmate saw it and spread the rumors.
the one i remember that fits this is never understand/out of control
http://www.mangago.zone/read-manga/never_understand/
Could also be this? http://www.mangago.zone/read-manga/itonaga_kun_no_koi_no_ito/
i feel like it's restless http://www.mangago.zone/read-manga/restless/
Hyesung was abandoned by his mom and he was raised by his abusive father. And then dojin had the audacity to say he looks like his mom? Welp...he raped hyesung when he was 20 and force him to get his child ┑( ̄Д  ̄)┍