Yang Ning was surprised and pursed her lips in a thin line when she heard his question as she wasn't expecting him to throw this question at her from nowhere.
However, seeing him asking this question again, she could see that he is aware of her condition at the Yang Household, otherwise, why would he bring up this topic with her?
There is no reason for him to do that.
She had already given an explanation about this matter at the Banquet, there was no need for him to ask her about it again.
It was obvious that he wanted to confirm the excuse that she gave the last time.
Moreover, Lady Yu Ling works in the Yang Household, and she sometimes comes to the palace to take care of the wedding preparations.