Theory of Love: Rak Khrai Tong Du Chai Kan Hai Nan

They began dating during their student years and, when they entered the workforce, they built a stable life together, ready to settle down. However, she still felt that the time they had spent together wasn't enough to change the status of being a girlfriend into that of a wife. Despite all the time they spent together where he was a wonderful partner to her, she had hardly ever had to do anything for him. Over time, their love started to fade, and all that was left was a habitual experience of having each other in their loves.
This became the best time for a third party to step into their relationship. The new woman who entered the man's life was an ordinary woman with nothing to compete with her. She chose to ignore her and believed she knew him well enough to trust that he would never cheat. Reality, however, was different. The man who had been in her life for so long had become someone she barely recognised.
This is the test to see if a woman who has never had to do anything for her lover can change herself to win him back.
(source : mydramalist)