It's heartbreaking to think that in the future ML will suffer another heartbreak along with his daughter when both of them find out about FL's secret after both of them growing attached to FL.
It has to do with his trauma. From the teaser both his wife and daughter maybe got involved in accident and die from it and that the reason he depressed. Maybe? Idk about FL background yet.
Does Nanya use other man just like ML as her pawn like slept with them and manipulate them for her plan, bcs from the preview for episode 9-10 some of the witnesses told that Nanya have affair with other man.