Ive been saying the same!!
It's so realistic, in fact the dude I was dating back then was almost exactly like this. He was funny and nice at first but found out how utterly fake everything about him was after just a few months. Even tried to force sexual stuff in public and then played the victim afterwards, overly jealous, threatened to off himself over the smallest arguments, etc... just basically trash human being (at least Jeongwon is handsome AND fictional )
Like Jeongwon being like this was definitely not out of no where. It was clearly shown in the beginning that he was fake af and thats usually how this shit goes
I am so sorry that happened to you and so glad that he is your ex!
I have also encountered manipulation in a previous relationship. I feel and understand Inwhee because I was actually thinking that I am imagining things, especially when he tried to change my perception of things. I felt weak and needed time to think that he was not giving me, instead he overwhelmed me with his feelings of love and guilt.
These problems seem so simple from the outside, but if you are in the situation, it's a lot more complicated.
I am actually impressed how realistic this is. This happens to more people than we realize.