CqlisMdzs:
LWJ may have fallen in love at first sight with WWX
That's my interpretation too - Lan Zhan falls in love with Wei Ying at first sight - in my first viewing. Just that he (Lan Zhan) doesn't know what it is. Despite refusing to let the Jiang clan into Cloud Recess, he still lets them in later, I think mostly because of Wei Ying. When he finds Wei Ying not in the group anymore (Wei Ying has gone to retrieve the invitation card), he waits for him to return. If Lan Zhan has no feelings for Wei Ying at that time, why would he stand there to wait for him? Wei Ying at that time is just another pupil of the many. Since then, Lan Zhan only singles out Wei Ying to punish. Though Wei Ying deserves it because he's the most mischievous of all, he's not the only one; many others also break rules, such as Nie HuaiShang (he reads pornography, drinks and gets drunk, fools around with the other boys, cheats in tests). Whenever Wei Ying's name is mentioned, Lan Zhan tenses up. There has to be something.
As for Wei Ying, I also feel that he is in love with Lan Zhan at the very beginning, but he brushes it off because he thinks it's impossible Lan Zhan would have permitted/accepted it. He prefers to spend time with Lan Zhan but whenever Jiang Chen comes with his sour face, Wei Ying would quickly go to placate Jiang Chen, throwing glances at Lan Zhan as if telling him, "Let me get rid of this dude first because he has a nasty mouth." Time and time again, he would try to ask Lan Zhan something (about his emotion), then quickly diverts it. For example, when they are talking about Mian Mian, Wei Ying is looking deep into Lan Zhan's eyes, searching his thoughts, but to disguise himself, he utters the name Mian Mian instead. We can see the instant helplessness on Lan Zhan's face, as if he is hoping Wei Ying would hint his (Wei Ying's) love for him first. After all, it would have been outrageous if it's only one-sided, so both think.