Skimmed your post on the way out the door. Would say if the parents main goal is cultural immersion, and it's a social group, can you give him special assignment homework for either extra credit or trinkets? Introduce the topic of giftedness, whatever you think would apply, to prepare the mother that maybe accomidations may be necessary in the future. Sounds like they want to be informed and make their own decisions because the sound like involved parents already.

Youth lives by personality, age lives by calculation. -- Aristotle on a calendar