I am what?!?

Yesterday afternoon we took the kids to our favorite Vietnamese restaurant for "Pho" or beef noodle soup. All three of the boys love this soup! They call it "daddy noodle soup". As we are sitting there slurping our soup down, Brandon heard the people next to us speaking what he called, "Chinese". Now he has heard Thinh speak Vietnamese plenty and Thinh's relatives were just here with us for a week in August and even Mason starting speaking it that week as well. So I am not sure why on this particular day he said, "Daddy are they speaking Chinese?" and Thinh says no they are speaking Vietnamese. Brandon was like, they are Vietnamese? Thinh and I answered him, Yes, and so are you. You are half American and half Vietnamese. Well, Brandon stood up out of his chair in amazement that he was actually of two nationalities and took his arm down the middle of his body as if he were cutting it half and asked which half was which!