Oh the OST. I must check them out then. Yes, the ex is absolutely annoying me with his overbearing behaviour when they are alone and then the rudeness when others especially his ex are watching. And if he forcefully hugs her, that is just too much. What a colossal jerk! Hope his fiance drops him like a hot potato and apologises to Qin Shi.
It was on wetv's official youtube channel. The videos that say trailer and the title says Ep22, Ep 23, Ep 24, etc. You'll recognise the show from the actors. The channel has English subs. https://www.youtube.com/@WeTVTaiwanOfficial/videos
May be I misread a comment that said the ex grabbed Qin Shi's hand and something happened at the wedding with the ex but the promos I saw had none of that. Worst thing I saw was the ex's gf takes over QS's office and makes her into a subordinate. Yes, it's bad of her but I found that twist exciting. May be because I find most of the people at her firm fake and they are finally showing their real faces.
https://www.youtube.com/@WeTVTaiwanOfficial/videos