3. When you argue about something he argued with his ex before.
“She got mad at me for forgetting our anniversary. It’s déjà vu all over again!” grins a man in his 20s. If his mind drifts away during an argument, he may be thinking about his ex and how she also got mad at him for the same reason. Watch his reactions closely, and if he stumbles while making a point in the discussion, that’s your “gotcha” moment. “You argued about the same thing with your ex, didn’t you?” Be playful, at least, so that the argument doesn’t escalate.