I recently met an American couple who have been living in Beijing for more than five years. Both love China, its people and culture. Even their children call China home. They would like to have more Chinese friends, but have been frustrated in their efforts.

They told me that they do have a lovely local Chinese couple as friends. But they have only recently been to the couple's home for the first time after having them over to their home on 50-plus occasions.

I started pondering whether non-Chinese could ever make true friends with local Chinese, and why the Chinese couple would behave this way. The first major issue could be "face", or mianzi: they could feel embarrassed that their place is too small or not good enough to have foreign guests around.

For a Chinese person, mianzi is paramount. It can be vaguely described as someone's reputation and social status as well as the image that one establishes in the eyes of others. It forms the integral part of the "Chinese way". It is intangible, hard to quantify, yet every aspect of work and life are reflections of this concept.

If inviting you to their home could make them lose mianzi then no matter how many times you invite them over, they are not going to return the hospitality the same way. More frustratingly they will never tell you why.

The second major reason could be the food - there is a Chinese saying, "Food is the sky". Often Chinese prefer eating out to home-cooked meals. With more choices they don't have to worry that they have chosen the wrong things to cook for you.

Another reason may be that some Chinese still feel a foreign friend is somewhat - well "foreign". They find it hard to see a person for what they really are, as the different color of the eyes, skin and hair are all barriers that they have to overcome - or maybe cannot just yet.

Remember modern China has only fully opened its doors to the world in the last 30 years or so. Most Chinese people have not had a multicultural exposure. They are not used to different physical appearances. Also many of them may not be familiar with foreign cultures - and what we don't know is usually what makes us scared and uncomfortable.

For example, my alumni and I often gather in Beijing. Having lived overseas for many years, I get used to the type of gathering where you and your spouse are both invited and meet each other's friends. After bringing him along to a couple of events, I felt a sense of uneasiness in the air.

But when I first asked if my partner could come along, the answer was "yes". Now I realize that means "no"!

When we were about to have another reunion, I asked again. One of my friends finally admitted that he prefers not having him around. Then to make sure that I did not lose my face, he explained, "so the conversation can be more relaxed and candid". "Because after all, he is still a laowai," he said.