I just read the spoiler and I regret it. The story is more messed up than I thought, especially the prince and concubine part...
You can read the spoiler from the link below:
https://forum.novelupdates.com/threads/surviving-as-a-maid.105138/
Yuri is so freaking crazy and a walking red flag but I can’t help but love him They are perfect for each other tho, only a predator like Yuri can keep a scaredy cat like Jiri