Based based based she actually hurt him a lot, even if it wasn't on purpose and we can see that through his low self esteem and the idealized version he has of her in his mind he never realized she did things wrong too
Yall are so blinded by jinhyeongs perspective without actually acknowledging her perspective at all. He never communicated ANYTHING with her and always deflected instead. How was she supposed to know anything he's going through if he shuts himself off everytime?
While he doesn't discuss personal matters like family matters, he has communicated his feelings like being uncomfortable with things and situations tho. He's said it but she always force things, being pushy about almost everything like socializing and opening up.
The author tried to lift the ex a little by giving us the perspective of Jinhyeong saying things like he lashed out on her cause he's afraid of being pathetic and she reminds him of his father, but his reactions are actually valid. She kept cornering him then when he's at his breaking point, she backs off a little and acts docile and all "I'm thinking/doing things for your sake *puppy eyes*" which makes him look bad cause now she's being nice to him but he's lashing out.
Example 1: Forcing Jinhyeong to come to the gathering by manipulating him (saying this is the least you can do for me), cornering him, then when he's at his breaking point, he walks out and this noona girl follows him acting like oh no what's wrong baby? Dw, let me do this for you. Then he lases out cause she's the root of the situation, he wouldn't have been in that corner if she didn't put him there, he wouldn't have needed her comfort if she didn't forcefully dragged her out of his comfort zone. But now he looks like the bad guy cause his gf is comforting him but he's not accepting it. He's not accepting it cause you're the one who created the uncomfortable situation!!
Example 2: Wanting to meet up when he clearly doesn't want to cause he knows that they're too high in their feelings. Still, she forces him, manipulating him that it's either now or never, meet with her or break up. He feels cornered, he goes to her despite knowing he doesn't feel well enough to hold the serious conversation they needed, then when he arrived, he's on edge cause he's only forced to be there then she acts like the mature one pouring out her heart, again going along the lines of I'm doing things for you, I actually love you, etc. But how can he talk properly with her when he's already said he can't right now? He's already on edge, you forced him into this situation yet again so he lashes out, now she's the one crying making him look like the wrong one when she's the one who kept pulling Jinhyeong here and there, putting him into situations he clearly said he doesn't want to be in, but yeah he's the bad guy for not wanting to be put in uncomfortable situations.
It's like like punching someone then giving them first aid kit then when the guy who got punched got mad, you'd say something like "Why are you mad? I'm healing you right now. You're such a bad person!!"
Idk bro, maybe we can argue that Jinhyeong's actions and words are a little harsh but he's on edge and feeling cornered, he's got his fight or flight triggered every damn time by this noona girl.