RedBluePurpleBlood

It was Seojin's plan after she pasted the missing child poster on his door. She was caught on cctv and he recognized her. He took it as a threat and placed cops at the venue to catch Aeri red-handed

I agree with she doesn't want to hurt him. He's trying his very best to find his family, like it's the last thing he could ever do in his life.

And I think if she tells him his wife is cheating their trust can be broken and they can't help each other.

It was always planned for 2 seasons before the drama aired.