Q&A What Question Should We Have the Polygrapher Ask?

My husband has agreed to take a polygraph test, so far anyways. He stated, "I'm sick of hearing about the polygraph test" and believes it to be a major power trip. He agreed when the marriage therapist recommended it. This is a marriage of 20 years, with a D-day a year and a half ago. He's admitted to pornography, multiple strip clubs, and lap dances. He admitted to having a physical affair in 2013 after his brother accidentally told me about it. He initially tried to convince me for over a year, it was an online affair only that lasted 2 years. Besides questions that lead to affair disclosures, what questions would be a good idea to ask in order to establish whether they are safe to continue a marriage. What questions would bring out major red flags and what questions would bring out major green flags in terms of him being a safe person?