answer: #Person1# finds that the Chinese always serve tea to their guests. #Person2# tells #Person1# it is a custom and good manners. The guests should better receive the teacup with both hands and bow his thanks. But if after chatting for a while, the host serves a new cup of tea, the understatement is 'I'm afraid it's time you leave'.
documents: #Person1#: Does tea-serving follow any special etiquette in China? Each time I dropped in at my Chinese friends'homes, their parents would offer me a cup of hot, strong tea, though they never inquired of me about whether I want it.
  #Person2#: You've got a point there. It is a custom and good manners to serve tea to a guest who comes to pay a visit. There is no need to ask if he needs it or not, or if he wants something else. It might be an insult to the guest if he is left sitting there without being served tea.
  #Person1#: So the guest is presumed to be thirsty and in need of some drink after the trip. In that case, I guess, in return, the guest doesn't have to drink it if he wouldn't like it.
  #Person2#: It wouldn't be considered rude behavior if he doesn't even take a single drop. But he'd better receive the teacup with both hands and bow his thanks when the cup is brought before his face. When the host pours hot water into his cup, he may also choose to tap his index finger on the table, meaning ' Thanks '. No matter if he likes it or not, it is impolite if he doesn't even lay a finger on the cup.
  #Person1#: So next time, I'd better take a few sips, to'save face'at least, right?
  #Person2#: Sure. The guest is welcomed by being served tea. But if after chatting for a while, the host asks servants or family members to serve a new cup of tea, or add some hot water, he is giving another signal.
  #Person1#: What does that imply, then?
  #Person2#: More often than not, the understatement is'I'm afraid it's time you leave'.