I'm only read the summary.. but can't find it again..i'm forget where i read it.. but for sure it's not fully translated yet. Mc is 2nd son on his family and kind of transparant. He have outstanding brother and sister. His family know about this but still neglect him.. his father even talk if something bad happened to them the one he will sacrifice is MC. MC hear his parent say this. And the mother just feel bad for him but do nothing. Later his father make him married to ML. They married than divorce. I'm forget after that.. only remember MC feel empty after their divorce.
Try this, maybe you will find it in that tag If you do find it, please tell me the name, it sounds really interesting https://www.novelupdates.com/stag/marriage/
Iirc before MC meet ML. MC live in school dorm. He feel freedom when he isn't at home. suddenly his mom come and ask him to dinner together.. he already know that his parent want him to business marriage. But his mom didn't say anything just make him learn table manner..