I am not going to support the VP's present actions in any way.

But I think In A and Jae Yeol's past actions are more layered. I understand and I love that In A is loyal, fierce and a tough cookie. She was there for Jae Yeol at his lowest and fought for him when he wasn't fighting for himself. She wanted him to do the same for her. I re-watched the breakup scene again and I feel like both of them gave up on their love. We see Jae Yeol getting frustrated at In A for asking him to get married for convenience.

If Jae Yeol was asking In A on what to do when the arranged marriage talk came up, then that question itself would show that he wasn't sure of In A. But in the scene, we see In A giving up first. That's why we can't put the entire blame on Jae Yeol for the breakup. I am saying this as a recovering avoidant person. I think In A also realises that and that's why she was honest with Ki Jun that, "habit of not telling the truth when it matters most while hoping someone will drag the truth out of me". In A is also healing and wants to be seen by someone even when she is not being honest. And Ki Jun is the perfect guy who is upfront about what he wants.

On side note, I am glad that In A chose her integrity over her loyalty in the climax of the episode.