My wife and I do this quite a bit. I'd consider us both well-read or media-literate when it comes to mysteries and thrillers, so we'll very often toss out our plot suspicions as we go.

If it's a TV show, we'll usually just shout it out, and if we get it right, high-five. Usually, that's only about an hour, maybe 45 minutes, so we aren't "spoiling" anything.

If it's a movie, though, and someone gets a suspicion, we'll text the other and leave our phones down for the rest of the film until we see if we were right, then discuss. That way, we don't ruin anything, right or wrong.

Film recs: The Game with Michael Douglas and Identity with John Cusack.