The only reason I got to episode 12 is that I'm intrigued by how they are going to turn around such a horrible storyline and characters. There are supposed to be 36 episodes in this, but I feel it's beyond saving.

Dear writers,
How come you fed us with flashbacks of the past to understand their relationship but suddenly STOPPED completely with the format? You could be using the same resource at least to gain some perspective as to whether the ML suffered at all! did he regret it? What happened to his life during those 6 years? ANYTHING would do so that maybe, just maybe, we could have some kind of empathy for him ( I doubt it, but still). And the FL? Your attempt to portray her tougher in the present time is meaningless, she doesn't seem to have evolved AT ALL. Maybe show us a flashback to understand what she has been doing all this time that she's still unable to have some self-pride. My god.

Dear ML,
You are the worst. Nothing, not your childhood or your career, justifies the way you behave. We've been through cold leads before, but even the coldest of them all would at least show an ounce of awareness. Disgustingly self-centered with no charisma whatsoever. Why in the world would you adopt a kid? are they trying to make you look more 'human'? Absolute FAIL. An irresponsible adult with no self-improvement in 6 years. An indifferent husband, a terrible father, and a doctor without empathy or sensitivity. WORST DRAMA CHARACTER I'VE SEEN.

Dear FL,
You were delusional in the past and still are in the present time. Again, probably the most annoying, clingy, pathetic, and sad FL I've experienced in dramas. No self-love or self-pride of any kind, but a whole lot of self-pity. Submissive to an unimaginable degree. You were young and in love -I'll give you that -but how come you didn't grow a backbone in 6 years? I can also try to understand that you need to interact with him for career purposes (which you never seemed committed to, to begin with) but...Carpooling with your ex? Faking mom to HIS son? Sleeping over with them? Toxic is an understatement.

Dear Kid,
I pity you deeply. You are surrounded by emotionally irresponsible adults.

Dear Friends & Family,
Why in the world would you want your daughter/sister/friend back with a man that has never - not once - shown her any kind of love or respect? just WHY?

Overall, these characters are as flat as my ironing table, they haven't made any contemplation, progress, or evolution throughout the years, non. FL's love towards him is borderline, and ML never loved her at all (convince me otherwise).
With the second lead entering the scene (he took his time) I hope you can show this woman what real love is so she can do some growing up for once. As for the ML, I couldn't care less.