I think it was his American wife who was the teacher, and even though he spoke Spanish I think he was from another South American country (Columbia?). So I guess I'd go with expat to answer your question. I'll check with my wife who will remember for sure and update this if I'm wrong.
EDIT: Actually neither of them are American. They both lived in the US for an extended period, but the teacher is Peruvian and the spouse is from another South American country.