So, in insight so far i feel bad for both of them tbh - like yeah, what heeseo is doing is terrible and i feel bad for taekyung (im interest to see how it will develop tho) but at the same time taekyung protected his mother who admitted (and he knew) to killing heeseo's mother even after she beat cancer (if she even was sick to begin with tbh) and started getting into politics and to make it worse, on the day he planned on leaving heeseo behind, he told him he could give him money and all his possessions and nothing else when he knew what heesseo needed the most was 1. a psychologist and 2. love and care.
I'm not saying taekyung deserve it, but at the same time i don't feel as sorry as I'd have if he did the right thing ig? And maybe he could have tried a different approach when talking to heeseo that night all those years ago, since he does know that he was highly emotional and unstable (specially after being told his mother was indeed murdered)