The other day, I was reprimanded for speaking English.
Yes, ok, it was rude (somewhat). but we only said a few words, spontaneously, after the hand was over and three no-trump scored.
Our opponents, women in their late 70's, may have grandchildren now spending summer internships or a semester of study abroad, but they themselves never did that. They may have spent vacations in foreign lands, surrounded by strange talk, but they never put aside their own language for the week, let alone a year. They just don't know what a pleasure (and relief) it can be to speak one's own language now and then, to speak it freely and at speed - not the careful and enunciated speech of multilingual meetings.
So we switched to French and let the little spark of home go. I don't imagine that made the lady on my left any happier: we beat them three hands of four.