Should We Continue the Course and Risk Hurting the Other Couples?

We are In our 2nd week in EMS online, my husband has yet to read a full chapter. On our story he was very vague. He continues to tell me he has not had a physical affair. But within a week of meeting his last AP I found a voicemail he thought he deleted, she referred to him as 50 shades and made it sound as if he was jealous that she took a call from another man because she said I was obviously waiting for your call it just happened that he called first. Then she said I know your there don't be stubborn. The previous "emotional affair" I asked him to take a lie detector (he failed). He still says it was wrong. I asked if he would take another one and he hung up on me. He said this isn't going to work if you don't believe what I say. Is this even worth staying in the course? I don't want to hurt the other couples that are actually being honest with their wives of what happened and truly doing the work.