Might be easier to invert the question... ask about their favorite encounter... their favorite porn stars... about videos or scenes they most fantasize about... about random encounters they wish to repeat... about first time, the best time, the time they keep replaying in their mind, the time they most fantasize about, about the one that got away, about someone they never had an opportunity to have sex with but fantasize about all the time... it's almost a Miss Manners moment - just get them to talk about themselves...
I'm a massive introvert, love nothing more than listening to others talk... and once, just once, an escort asked much of the above, and it was almost impossible to get me to shut up.... he was a regular for years as he somehow understood what made me tick...