People who are uncomfortable in social situations tend to become drained when they have to socialize for an extended period. Allow him time alone without getting offended. It's not about you; your friend just needs time for quiet to recharge. Although it may not seem like it, your shy friend may be terribly uncomfortable during the entire interaction. He may be anxious to get away to process the exchange. Outgoing folks might think all their shy friends need to become social butterflies is a little push. Shyness can be a serious social detriment that inhibits people's relationships and work lives. It's not something that will go away by challenging the person to take a risk. If you take this route, you can end up causing distrust and making your friend retreat from you. You might suggest a few "exciting" things to do with your new friend, but if he doesn't seem interested, don't force the issue. Another quick route to ruining the friendship is commenting on your friend's shy nature. Treat your friend just as you would any other. There's no need to point out his shyness.  Asking why your friend is so quiet or introducing him as 'the shy one' can be quite insulting. This will probably annoy your friend and cause him to be even more self-conscious. As a result, your behavior may actually make him withdraw even more rather than getting him to open up. By doing a bit of research you can better understand and empathize with your friend's social behavior. According to science, shy people tend to feel awkward or fearful of social situations, particularly when around new or unfamiliar people. Your friend may experience a pounding heart or an upset stomach. He may think that everyone is looking at or judging him.  You can be a better friend to a shy person by recognizing that all people feel shy on occasion. Your friend just appears to be extremely shy. He probably isn't being shy because he doesn't like people or even because he wants to avoid them. He is simply uncomfortable in most social situations. He probably...

How would you rephrase that briefly using Vietnamese?
Đừng cá nhân hóa vấn đề khi người bạn ấy muốn được ở một mình. Đừng cố ép người bạn mới làm điều khiến họ cảm thấy không thoải mái. Cố đừng hỏi vì sao một người lại nhút nhát hay hành động theo cách thức nhất định. Hiểu sự nhút nhát của họ. Hãy kiên nhẫn.