My Isaan adventure

[sglad]

Every Thai family relationship is carefully defined, so that word for the son of my father's older brother is different to that for the son of my father's younger brother or my mother's older brother.

No, it isn't. Cousins aren't differentially defined. The son/daughter of my father's older brother, the son/daughter of my father's younger brother or the son/daughter of my mother's older brother is my cousin or luuk pee luuk nong or more generally yaad or relative if the speaker is not sure of the connection or doesn't want to go into specifics. Actually luuk pee luuk nong is broad enough to cover cousins, second cousins and cousins not related by blood but through marriage.

My father's or mother's older brother is my uncle or lung. My father's younger brother is my aa.

Nice try at giving the appearance of authenticity (although I'd keep away from the Thai language if I were you) but an almost passable story woven around YouTube videos. C+ for effort.