This drama got on my nerves because the MAJOR issue could've easily been solved if they would've just TALKED.
The Ex-girlfriend had been trying to break up the ML and FL for the longest and finally succeeds when she secretly changes the divorce agreement between the ML and FL. Once the FL finds out she gets mad and leaves for 3 years. Comes back and is still mad even though the ML and her own friend tried to explain the truth but she so hell bent on hating the ML she doesn't listen. Its only in the last episode when the FL is about to get on a plane, the ML comes and tells her he loves her and she loves him (after she came back after 3 years her and the ML basically fell in love with each other again, but she refused to let herself really fall for him because she was still mad at him) So she tells him she loves him but can't be with him, so he walks away all sad. THEN mins later she gets a text from the ex-girlfriend (who at this point realized the ML would never love her, and that she messed things up) confessing EVERYTHING and how it's not ML fault, NOW the FL decides she no longer hates the ML and runs to him and kisses him.

SO, F*CKING STUPID!! All of that could've been solved if they just communicated.