A lesson I’ve learned from the world of pickup sports: One surefire way to frustrate teammates is to keep them guessing for what you’re looking for.

In basketball, for instance, just get mad when they pass the ball instead of shooting it, and then get mad the next time when they take the shot — and make sure it’s unclear why. As long as there are mirky expectations, and you make a big deal of when these expectations aren’t met, frustration is sure to follow.

The same thing can happen in all of our relationships. When expectations are clear, people will know when they’re meeting them, and when they aren’t. But if they’re unclear, it’s only a matter of time before frustration will show up.