They are pretty much established. There are hints here and there that Zhengxi feels the same way about Jian Yi. But I agree that the storyline about Jian Yi disappearing is still unfinished. I don’t know if it will ever be given that there’s already a timeskip.
I can never get a good read on Zhengxi. He’s so inexpressive that it feels like he didn’t want to lose his friend so he agreed to date him? At least with Mo there’s clear actions that shows his feelings are mutual. The only clear sign from Zhengxi that I’ve gotten is in ch. 467 where he says he’s serious about taking care of Jian so he doesn’t have to work almost like a housewife.
I was wondering something...
Spoiler ahead about old old old arc/chapter...
When Jian Yi declare to Zheng Xi he love him (after the kiss scene), Zheng Xi said that he known about his feeling, he was surprised after all but he didn't respond clearly... After that, this couple was like tossed on the side to let Mo and He Tian be developped with She Li Arc.
It's me or we don't have no more story arc about Jian Yi (kidnapping arc etc) and the developping of this couple?
I love Mo and He Tian but the first couple story seems unfinished to me and it was my favorite one #－.－)