Maybe you don't get it, but familiar bonds especially parents can't be easily broken off, especially hye sung only have his mom back then to show him love so he's very attached to her, and again don't project your own self to hye sung or the others characters, and again if you don't read the others manhwa the reason the mom don't contact hye sung because she's afraid that hye sung will hate her and better off without her, the thing is that people make mistake especially hye sung mom is very young and don't have anyone to hold on to she's probably still very childish at that time and think she should go and search for something else
You're commenting this under every comment but being super hypocritical
"Don't project yourself onto him" you're LITERALLY doing that yourself bro. That's great you're working on your own relationships but let others go down different paths without judging them. Life isn't so black and white to say one rule applies to everyone.

I'm still pissed to the mother because why did you have to abandon your child in the first place. You could just take him with you or something, or you guys just escape together, but why decide to abandon your child? Im also pissed at the husband cause wym you supported the mother financially without your wife's consent? And the son, the son pissed me so much because of the recent chapter he fought with his mom because of the grandma. I know that's his mother, and he should forgive him by any chance, but for me, he should not forgive the mother. First, she abandoned him. Second, she didn't even contact him for all those years or reach out to him. Third, i think the grandma is just leaching out her son's husband money (my opinion). That's why he should not forgive the grandmaa!!!