To start with I must say, the female lead was serious when she said she is no different than the high school girl. She didn't want to do so many things and yet ended up doing them and each of them prove her to be a selfish, gross woman. But here's a catch - She was also craving for a man who would understand what she wants and would accompany her thoughts. This is the reason she could never say she didn't like the teenager boy. Bcz he had given her the feeling of being heard and understood.
Although the plot made us look down on her character and made it look legally and morally offensive towards her but as per what we could arrive from the show, she never had a proper friend whom she could rely upon. So she had always wanted her boyfriend to be that friend for her and mess herself up by being indecisive.
The sex#al potrayal was not totally unnecessary as it made the viewers realise the true feelings of the characters but it was too much erotic must say atleast for a teenager boy. Obviously it was shown in purpose to bring realistic picture but still it was too much and f lead made it look cringe sometimes. Still I believe the rumor punishment was enough for her as she had to leave the only job she had found after so much of hustle. Also it made her realise some facts that she had to leave that boy to let him think properly about his future and it is better that it is upto us how we imagine if they will be together later on.
Coming to Fu kun, he was a pretty nice guy according to today's standards. Although getting a chance, he did not step forward towards cheating with her gf. And I personally felt the female lead did not like him from the beginning as she also mentioned sometimes in between that she chose him because he chose her.
That's why I believe we should not go into a relationship if we are not sure if we are actually interested in that person. If something goes wrong, a long relationship might wreck up into pieces silently and the one with actual feelings would sink in desperation. Although it seems pretty easy to move on in shows, but irl it is worse.