Play with an interlocutor?
I don't know, just wild guesses, but I think it is an expression, "how things play out", sort of like how they work out, and the idea is that from our perspective we can plan things but what happens is something else, the "unpredictable" is factored in. The unpredictable being the rest of the people. So "play" is really more descriptive than "work"...also that idea Shakespeare had about all the world being a stage and people are the "players"...
And it's a lot safer if you can try to get a larger vision just inside your own head, you get to "play" both parts, lol...
But it's a lot like masturbating too, lol.
(Don't even know exactly what interlocutor means...)
I love to talk on the net, it's the same as talking inside your head, but a bit easier to make the Other seem "real"...sometimes the other really is real...people listen and talk back.