There are so many factors this play into Hajin's personality and why he's acting this way. One of the biggest deciding factors though is Jaehyuk. He's extremely manipulative and knows how to pull the right strings to get what he wants. The other problem though is Hajin's people-pleasing habits. He doesn't like troubling others with his problems so he keeps trying to stop the situation that he's deemed the most problematic but since people are stubborn beings, he can't help but long for Dokyung.