I can't really blame Chi Yan for his actions (no cheating I guess? Base on how obsessed Gong is towards the story and the interaction he had with the other guy), given that he has had this misunderstanding for years. Not to mention, his partner's nonchalance about emotions and actions. Throughout the story, I felt that Chi Yan didn't have any assurance or security in the relationship. If he did, that misunderstanding might have been addressed earlier. Furthermore, Chi Yan was the one who reached out to Ji Hiye, yet Ji Hiye didn't react or express any curiosity when the sudden break up arise despite knowing who Chi Yan is and after that based on Chi Yan's actions alone you can comprehend that there's something on him but Ji Hiye keep on insisting on the break up instead on asking what he really want, it is clear that he is very open about his feelings that there's something he wants to convey. Maybe if Chi Yan said the reason there might be no problem.

This story is mainly like break up because the Gong want some reactions toward the Shou and as usual misunderstanding from the past and fear but the shou just nonchalant about it cause he got irritated on the reason that the gong given and move forward, so the Gong panic because he can't really go on with his life without the Shou, So he keep appearing in front of the Shou to express his emotion but the Shou just want to keep going in his life, the Gong disturb him and the topic of the real reason of the break up discussed and tadaaaan they're okay. So abrupt.