If I flew with a QWI, I'd ask an esoteric question about the radar/missile. Close my eyes, and listen to him blather on (You had to chuck in the occasional "OK" to keep him motivated).
I guess the same would be true with a QFI, only the question would be about the secondary effect of something boring.
Flying with a Flt Cdr, I'd ask about promotion prospects...same result.
Flying with the boss, close eyes shortly after take-off...they needed no invitation to blather.
Flying with a mate, talk about girls and beer for 8hrs.