beta
My theory is that his brother is the one who taught sexual stuff to Seo-in and Seo-in grow up thinking it was normal.
He probably put a stop, they must kissed one last time as goodbye because brother wanted and Yeongwoon saw them.
His brother was blond but somewhere in the story he died brown hair apparently ... Or maybe it was always light brown and it just looked like blond in the chapters when they were younger ...
Brother started bullying Yeongwoon because Seo-in didn't want to fool around with him.
There must be some kinda of fight and Yeongwoon got expelled or something. Along with the debt problems ... So he run.
Maybe Seo-in must have an inkling abt the brother bullying Yeongwoon when he was away because when he went to look for him, a classmate said he had no right ... Or maybe he didn't add up and thought it had to do with him instead . Who knows.
Soo i guess the brother died after Yeongwoon left... Heo-in mother said they have eaten together when they were in college, probably around that time, maybe Heo-in and his brother fought, brother got in an accident and died.
Part of his family blames Heo-in, the other part takes his side.