
Honestly, the second girl seems to really love mincheol. He is gonna lose another good girl at this rate.

Good girl? I mean she's indeed in love with Mincheol but she's not a good girl. Even after knowing that Haesoo was his ex-wife she didn't give a damn about her and kept pursuing Mincheol.
She's so stupid thinking that a guy that cheated on his wife would be loyal and good to her.
Mincheol still loves Haesoo in his twisted way, he doesn't feel anything for that other girl. Sure Mincheol is a bastard and he doesn't deserve happiness right now but even that other girl doesn't deserve happiness, she's getting what she deserves right now. Karma is a bitch we all know that.

You're right maybe he did, I honestly don’t remember right now, but I do clearly remember that Mincheol and Haesoo had a very obvious fight in front of Ari, where Haesoo said something like, “How could you do this?” What I’m trying to say is, it was obvious they were in a relationship, especially since Ari was literally standing right there and heard everything.
I understand that Mincheol might have manipulated her a bit by claiming he and Haesoo weren’t together, but she’s still a grown woman. She should’ve paid closer attention to the situation. She saw how hurt and angry Haesoo was when she saw them together, so deep down, I don’t think Ari actually believed Mincheol’s explanation. She just chose to accept it because, selfishly, she still wanted to be with him.

Someone clarify the timeline here pls. So all those bad things and miscarriage happens in their first life and they dies and enter the world of huimin’s paintings. Later they exit the painting world and then they go back in past to the point where they reunited again at auction but huimin thinks he entered the world of novel and that the world of the painting is the real life before novel although he is wrong.

That pretty much correct. Now Huimin knew the 1st life Huimin was actually him. He accepted it without any trouble. His personality stay the same like him in the painting's world; cheerful, not too serious, drama-free. Honestly, his current personality is the reason why there's not much angst for their current life.
I am not reading after chapter 70 until it gets to the part where they are both happy without bad guys trying to hurt them. Still gonna be lurking in the comment section to see if it’s time to read .