Or maybe he should just make it clear to her and her family that he who he is and if the don’t like it screw the whole bunch. If the woman truly loves him she’ll tell her uppity parents to back off. If she spends her time coaching him on the proper answers at the supper table he will look pathetic.
He should find something that each parent enjoys (flyfishing, golf, sailing, horses etc) and become an expert enough on that to ask intelligent questions and carry on an intelligent conversation on the subject. Also come prepared with some interesting topics he is knowledgeable about and ask their opinion on those things. Turn the tables.
I’ve been there. Smarter than the whole bunch, but not of their lofty social status. Once they figured out I was the smart one at the table and could converse on any subject the testing stopped.
This can be a process, to learn the family dynamics. And also, what topics are hot button issues. Politics and religion are often hot buttons, but there can be others.
Health food and vitamins were inflammatory subjects around some extended family in my experience. You sometimes have to just feel your way and learn what is acceptable so you can get along with people.