Prince Reigen was someone who was known for his bad habit of sleeping with some of the famous prostitutes in Breviel. He was very picky, but that did not mean he wouldn't invite a girl to warm his bed at night.
The servants often talked about him behind his back, and they even talked about how the prince had changed his habits recently. After Shovalon's princess stayed in his bedroom, Prince Reigen stopped inviting prostitutes.
Prince Reigen was someone known for his wild behavior, and when he said that he wanted to spend the night and do something to Shovalon's princess, it might sound wrong for an outsider to listen to their conversation.
But, only Princess Ievna listened to the prince's words in the bedroom, and she knew very well that Prince Reigen would not be able to spend the night with her.