I feel like people in the comments are being too harsh. Their relationship is just a web of miscommunications…
I think the problem some people here have is that, while we are being shown Hyun Woo on a guilt trip throughout the 8 episodes for even thinking of divorcing her, thinking only of his freedom when he got to know about her illness, and wanting some kind of alimony due to the suggestion of his friend, Hae In is generally shown as more angry on the matter rather than feeling guilt for her wrong behaviors in the marriage. I know we haven't been shown the proper picture yet about what damaged their relationship, but Hae In is getting more victimized in this situation just because she has an illness, past traumas, and, as a woman, had more trauma due to child loss. Hyun Woo is at least seen trying to communicate his problems with the marriage, but we don't see that from her side as she becomes rather petty in comparison by trying to hack his phone, showing her anger by humiliating him in front of others like her employees, which, by the way, decreases his credibility in front of others, tailing him, and even being rather detached about the whole situation. Even after the divorce, we are only shown that Hae In gets a sudden epiphany about wanting to leave Hyun Woo so that he can leave behind all the humiliations he has faced. But we don't see her trying to mend the relationship or at least communicate. One of my favorite dramas, 18 Again, was like that. The leads there were just the opposite of this couple. The male lead was not willing to communicate while the female lead was a saint and very understanding. But the thing that show did better was they were both equally shown the wrongs they have committed in their marriage throughout the show. They both had problems, but both were apologizing and trying to mend their relationship with proper communication, while here we only see Hyun Woo having a character arc where he is trying to save the marriage, while Hae In's character arc isn't properly developed in this regard.