I think that what Haejoon said at the beginning has some reason, I also see that if Haejoon had said everything to the contrary, Eunyung would still be upset, even worse😿
But now Eunyung feels worse because they told him he was the only one with issues, he even blushed because he was ashamed that what he was saying about him was true
And again, when Haejoon was feeling miserable for his life, Eunyung enjoys seeing that there is someone just like him having the same hard time