beta
My understanding is that Yuta was (and probably still is) in love with Seunghyun. He felt as if Seunghyun felt that same way until SH ‘abandoned’ him do the blonde boss. Thus, Yuta now thinks SH is a coward, and was just using him so he wants his revenge on him for how he made him feel.
According to chp 16, it looks like Yuta went through great lengths to try to find SH and that is probably how he managed to be in the area during the wedding. Because we as the reader don’t really have the full timeline of what happened, we are getting bits and pieces that serve as memories which is primarily noted by the darker background.
In the latest chapter it looks like SH answering the phone under a different name was one of the reasons Yuta felt as if SH left him behind and didn’t truly care for him. Just my thoughts, could be totally off.
I don't think SH did anything deliberately yuta was just not a priority. Also yuta is a business magnet now so maybe that's why he was at the wedding. Try reading more chapters on MRM they are translated
I understand Seo in is upset and ‘wants to make things right’ but to cut Yeongwoon out without any communication is so shitty. YW is the victim and he was so happy that the relationship was progressing that by doing this he’s just getting hurt again. So frustrating.