Amidst where they were at the moment, Canillas highly hoped that Joanna was only teasing him. It was completely fine with him if she used the present moment to return to him for what he had done to her during their togetherness, as he would gladly see that as an amusing dynamic in their growing relationship.
In his eyes, it was a way more interesting thing than Joanna uttering a serious request that he knew it would be hard for him to dodge.
However, seeing her calmly nod her head with a readable expression that remained the same no matter how many times he blinked his eyes, it was then he let out a heavy sigh. He was not blind to not be able to see a clear sign that she was not teasing him.
An amusing dynamic in their relationship had not yet come. In other words, she indeed uttered a serious request.