When you suspect a lie and want to reveal it, you must start the conversation, as usual, to build rapport and be just socially interactive, no compromising, heartbreaking or devastating questions. Keep up the small talks, like the swedes always start talking about the weather. It is like we ar obsessed with the weather. It is the icebreaker in elevators, job interviews, dates, you name it. I really don’t know why, maybe we are too insecure to address more important topics. We always want to find consensus and I guess weather is the topic for that.
But for revealing discomfort or even a lie, the weather small talk is to assess a normal picture of how the other person interacts and talks. After small talk i.e. short cultivation, in the spy world it may last for months, you can fire the crucial questions, where you can expect reactions. To get the best result, these should come quickly, and the other is unprepared; like a whip of a stick. However, it is not enough for a single rap, but the questions must be structured and planned in the correct order. In order to assess and evaluate the answers and the body language, the best is to have a talk recorder or second best, have a colleague with you who doesn’t interact but can focus on observing.
Because once you interact with yourself, and you are caught up in the conversation, it is difficult to notice all the small bits and pieces of the other person's response to your quick questions that you hopefully fire off and catch the person by surprise, which will reveal a lot of tentative discomfort as Robert Kiyosaki said:
”Confidence comes from discipline and training”