The French don’t say “oh I did a faux pas” or omigod I just got deja vu!!
After a few years of trying to convince people that they must use these expressions I have realised that they really don’t.
And as a mystical Irish person, I always get deja vu and I always use it the way we do so i.e. “argh serious deja vu there”. So himself is like “tu as vu quoi deja?” which means “what did you see?”. Thereby generally follows the explanation conversation where he reassures me that the French really don’t say that. It keeps things pepper.