Rex could sense the intention behind Iris' flattery, she wanted something from him.
But then again, from the others' point of view, Rex was the Emperor, who killed the Fifthborn and also created a lot of powerful figures under his reign. He could manifest things from thin air that was unrivaled in mortal's comprehension.
It would be weird for Iris, who was in his presence to not take her chances.
One good item from Rex would set her for life.
"Naela, can you check the progression of the Divine Chalice?" Rex asked with eyes closed.
He was still enjoying Iris' head massage.
Upon hearing this—Naela glanced over at him and saw Iris was also looking at her peculiarly, and this somewhat made her uneasy, "Your Majesty, I don't think leaving you alone in a room when you don't know the place is a great idea"
Despite the carefulness of her words, it was obvious what she meant by that.