Xing got down from the roof when Rijun approached her and the Emperor got back into the Study after Rijun greeted him. Their relationship did seem strained.
But, Unlike Weiye, the first thing Rijun noticed was the White Tiger Token hanging in Xing's waist and gave a polite bow.
"Can you tell me what happened on your way here?", he was polite as he talked. Not only this woman inquired him about Xu Mama but also she seems close with his father spending time with him a lot lately and his father seems to be in good health lately after he met her. Now he had learnt that she is the bearer of the White Tiger Token. So it is his duty to be polite with her.