A nod of thanks with his smile tugging at the corner of his lips a little more was given in response to her compliment. It wasn't common to actually say 'thank you' in China. Unless the person had really done something you were particularly, deeply grateful for.
The sudden shift in her demeanor caused his brows to furrow. What in the world had just gone wrong? He tried to replay the situation over in his head again, but nothing had gone horribly wrong. They had just been talking.