Our Ball Begins at Moonrise

Here is the challenge for the magician Iris Elaine! Just when she was about to suffer a mysterious death, a woman came to her side and swapped bodies.
For that reason, she possessed the body of the queen. So now Iris’s identity is the queen?
Emperor Sidrain with red hair walked through the door. He walked away with a very annoyed and frustrated face. As he walked over to him, he grumbled and grabbed Iris’ wrist.
Her eyes widened in surprise, when he appeared unexpectedly in the middle of the night.
“I don’t feel comfortable doing this to you every month.”
He said as he gritted his teeth.
“But it’s up to you and me for an heir to appear. If you keep acting like last month, I’ll make you miserable.”
What do you mean?
“This is the only thing you can do as a queen.”
What nonsense is he talking about? She really didn’t know what to say.
“Okay, let’s create an heir, Your Majesty.”
She said in a sarcastic tone.