Ooo chess, but why so many questions about openings??!?! Hmm, I guess there's little else to discuss. Unfortunately openings are not 'real' chess, are they?
I'd rather just play a game. If somebody talks about us playing such-and-such opening after the event, I usually respond with something like "That's interesting, but I did not know what opening we played".
There's nothing wrong with a little white lie I suppose, and I don't mean about not knowing the name of the opening.
If they don't get the message they might continue with hypothetical questions about alternative moves and potential parallel universe positional outcomes of the game. That usually leads to a response like "but we didn't make those moves, no it's not interesting to talk about these things, I played the game I wanted to play, not all possible other games simultaneously. I don't want to rewind and explore other avenues of possibility, that's just speculation about stuff that didn't happen."
A brave adversary at this point might say "You're no fun to talk to".
To which I would reply "but I am fun to play, yes?" and start setting up the board for another game.