1) they do keep it a secret until after this Hong Kong trip I believe they didn't officially announce it or anything the staff just guessed yi-hyun liked Liu one-sidely then saw it was mutual after sometime.
2) They broke because Liu kept it a secret that he's a Ghost (a special type of alpha that can turn betas into omegas) and that Yi-hyun is his diamond dust (a special type of beta that can sense pheromones and can turn into a omega from a ghost). Liu was gradually changing him without him knowing and he found out by accident. So they broke up and Yi-hyun moved away for a while.
3) They never even entertained any other partners during this time. They missed each other and pined for one another until they finally met again.
4) They do that shit raw Every. Single. Time.. I don't think condoms existed for them
You're welcome for the spoilers
Here's the link!
https://oceanstale.com/diamond-dust/dd-2-5-the-scent-is-a-drug/

anyone please feel free to spoil me if you can answer the following:
1) do Kun and Y make their relationship official towards the phantom staff or do they keep it a secret? And if they keep it a secret when do they announce that they are dating?
2) I know they end up splitting up for some time but what is the reason they take a break with each other?
3) Does Kun ever cheat on Y or the other way around?)(>….< I hope not)
4) does Kun and Y do it raw or do they use condoms?…. (sorry not sorry but in yaois I have a thing for them to go at it raw)
Thank you in advance for spoiling me!