Just finished rewatching this. Honestly some of the best acting from a FL I've seen in kdramas. This show is depressing af, but sometimes you need that, and FL had me distraught and grieving for her throughout. I love that she vented her hurt and pain, but I also appreciate that she didn't go full revenge mode at the expense of her own morality and dignity. The whole point of her is that she's a genuinely kind and decent woman, and if she'd truly gone dark it would've been a let down, and wouldn't be true to her character.
ML was terrible and selfish in a realistic way and I have searched high and low and have yet to find a drama that can give me the pure satisfaction I feel in that scene where he gets the photos developed and just sobs in the street fully realising the harm he's caused himself. Exactly as his mother said, he had no idea what he'd cost himself, and no idea what he'd lost. Through his own vanity, fear, and selfishness he destroyed every shred of happiness he had, and noone felt bad for him.
Yoo Ri was wonderfully acted too. I like that she wasn't just a mistress or an illegitimate child, she was a fully fleshed character, who behaved selfishly and victimised herself to such a degree she thought she was being noble at times, and weaponised her trauma as an excuse for her behaviour. She was toxic and I'm glad that even though they gave her enough trauma to explain her broken moral compass, they did it in a way where it stayed completely unforgivable. Noone chose her, noone forgave her actions, and she stayed miserable. She did officially end things with him, but that was after knowing he didn't really choose her even when his marriage was over, and he was only with her out of pity, and she finally realised that was meaningless. I'm a petty asshole so it delights me that the people who did terrible things were miserable at the end.
All the coworkers were wonderful too, I cared just as much about their stories as the main one, and they were all realistic and acted beautifully. Honestly whoever casted this drama, well done. The writing too was wonderful. There were no empty spaces, and every conversation felt real purposeful.
If this were a fluffier drama they would've given FL a new love interest, or hinted at one as a real F U to the husband, but I'm so glad they didn't. She told him when she gave him the papers that for 10 years he had been the most important person in her life, and how they finished the drama shows she is focused on making herself the most important person in her life, which I love. She has a wonderful support system, and can live happily, and he can die alone.

Liked: This drama was full of strong female characters, who were totally realistic. They were strong, but not caricatures of empowerment. They struggled and suffered but found strength in themselves and in eachother.
The acting was phenomenal from everyone involved.
The pacing and the story itself was depressingly real.
Disliked: Honestly nothing.