I think that the previous theory in the comments were correct after watching episode 13. As per the plot involving…
There’s still hope that it’s a misleading conclusion. Because Ji Hoon only heard the end of the sentence from Yeo Jin. It might not be about an affair at all. It could be just another misunderstanding. Or it’s just me grasping the last straw of hope 😂😂
I sometimes got confused and mixed up Seo Jung Yeon’s roles here and in Payback. They should at least give her different hairstyles 😁😁. But I prefer her character in Payback because she’s honest there. Anyway she always acts very well. I also like her in Our Beloved Summer.