Watch A Flea in Her Ear

A wife thinks her husband is having an affair because he no longer makes love to her. She talks her best friend into writing a letter to him as an admirer, asking him to meet her at a hotel. He's not interested, so he doesn't show. Along the way, the letter gets into the wrong hands. It turns out to be a hysterical case of "he said, she said" as you have different couples meeting at the hotel with each one of them thinking the other is having an affair. What innocently started as a test turns into a catastrophe.