I think its because of the tune that WWX used when he summoned wen ning
OHHHH omg if it's that early then wei's attempts in being a tease for lan to be disgusted and leave is so much funnier now. thank youu
Welcome (≧∀≦)
*SPOILER!!!!*
Actually it was the tune that Wei WuXian used to calm down and lead Wen Ning away from everyone that told Lan Wangji who he was. Not the tune to summon him.
It's the same song Lan Wangji sang to Wei WuXian after they killed that tortoise in the cave because Wei WuXian had a fever and was bored so he asked Lan Wangji to sing for him. At least that's what happens in the novel (I know the manhua hasn't gotten that far). If you haven't read the novel you should, cause that part of the novel is so cute.
THANK YOUU i just recently gotten into mdzs so i was unaware
But at what chapter did lan figure out wei's identity?