I don't feel like it was a forced drama. It was a lot of coincidences, try to see it through YuYang's eyes:
1. Wang Ming and LiHuan are seen talking together. Twice. And always when YuYang isn't around. Yeah, LiHuan isn't talking, but... well, he hardly does.
2. The scheme was about making YuYang suffer a heartbreak. Yeah, he knew on the spot that his heartbreaker should be Zhang JieFeng, but he only knew this much. Who else could be involved
3. LiHuan, at first was just an annoying freshman to YuYang, but later he becomes very approachable. Plus, they are all from the same form room! If LiHuan wasn't directly involved in the scheme, then at least he would know anything about it, right? Wang Ming isn't the kind of person that hates anything in secret. Then why didn't LiHuan say anything?
These are just details. The point is that it does, too, feel kind of forced because things have just been going too smoothly for the to-be couple, and the author decides to bring in some drama to prolong the series.
The thing is, this can all be planned to begin with. The premise itself can be that it's so loose that the story can get sidetracked by new plots and drama. I'm not really a fan of this, but it's still fine. However, I feel that there could have been better ways to go about an event like this. It's just kind of a stupid misunderstanding, in my opinion.
Ok, yeah, go ahead, call them idiots, and then go ahead and hastily misunderstand on your own. Oh, and definitely don't try to confront him or anything, that would be too logical!
It was pretty obvious for us, even before we knew that they were just talking about an assignment, that it wasn't him who was involved, but this guy can't even stop to think for more than two seconds?
C'mon man. This feels like forced drama.