Does anyone know whether there are Polish-Vietnamese couples? If any, I doubt there are many. Vietnamese tend to live among themselves and are in small businesses related to (Vietnamese) food and cheap clothes imported from Vietnam and neighborhing Asian countries. The first Vietnamese arrived during communism as "students" so obviously they do speak Polish and certainly most of them have the Polish nationality but I seriously doubt that they consider themselves "Polish" first ;). Asians abroad live in ghettos and according to what I have always heard, they are pretty racist ....
