Probably the main character told to that guy that he likes him but he refused him because he already had a crush for someone else. And maybe after that confession the silver haired guy didn't attend school anymore?
So, you mean that, Yuyang's dream is somewhat he hoping to happen for Xiang telling him that Xiang like him back? I mean, after a long time Xiang not attending school he suddenly appeared and accept Yuyang? I mean, that's only what Yuyang's hoping to happen? Ah.. Wait.. I think I said it twice. Ah.. I don't know how to explain what been playing on my mind, I hope you can understand what I wrote..
tbh I hope you can understand me ahaha >>
Btw today I read the manhwa of the silver haired guy, he actually refused our main character and then I think they just went on different "roads", actually the silver boy had a lover too.
So yes, I think he dreams about that guy time by time, but after the reaction of Yuuyang, maybe he didn't dream about him lately so he thought it was frustating and weird, and he was like "why am I dreaming about him again?"
Is that just a dream or it was really happen? Because the way Yuyang say it like, it already happen before that it keep appearing in his dream..
If that's only a dream, I'm relieved.. But if somewhat happen I will be total angry, what happen to Xiang parner?