Well, obviously those who kidnapped them must have drones, or magic items to spy on them. But, if they wanted them to have to sleep in that same bed, why did they give them a huge house? Why did they put beds in the other rooms? I guess it was just a contrivance to show they were willing to conjure up a storm and soak them to get them together.
Obviously, this being a romance story, there is less than 1% chance that they don't end up together. I would prefer it if the story actually followed the description written on the home page and they dedicated all of their time to getting off the island and getting even with those who kidnapped them.
I would also be perfectly happy, if they decided to stay together, but when the got off the island, they go live in the territory of an enemy of the Empire, and help that enemy screw over those responsible for kidnapping them.