Lately, I've noticed something strange about my wife Rena's behavior. While sleeping together, she suddenly starts convulsing or moves around as if sleepwalking. She doesn't answer her phone and comes home late at night. Feeling like she's hiding something, I installed a hidden camera in our home. When I returned from work, I secretly checked the footage. To my shock, I saw a man entering our house in the afternoon—it was the doctor from the local health screening. The doctor touched my wife's breasts, murmuring, "Your nipples are burning hot," then pinched her erect nipples hard, making her cry out in surprise. Watching this scene, my heart pounded wildly. My wife appeared extremely aroused, and I couldn't stop wondering—who is this man, and what exactly is going on?