He thinks that Dojin was planning to ditch the baby on him and leave him as a single parent. I know it doesn't justify him running away and he only heard part of the conversation before jumping to that conclusion. But you have to understand that he didn't want to go through with the pregnancy in the first place, and he was vulnerable after giving birth. Hearing that and thinking that Dojin had an ulterior motive all along, would scare him of course and that fuck face feeding him lies doesn't help at all.
He thinks that Dojin was planning to ditch the baby on him and leave him as a single parent. I know it doesn't justify him running away and he only heard part of the conversation before jumping to that conclusion. But you have to understand that he didn't want to go through with the pregnancy in the first place, and he was vulnerable after giving birth. Hearing that and thinking that Dojin had an ulterior motive all along, would scare him of course and that fuck face feeding him lies doesn't help at all.