My wife, who had been using a flip phone until recently, finally switched to a smartphone. "I'll only be in contact with you anyway..." she said, not wanting to change her phone model, but as soon as she switched to a smartphone, she became addicted to it. I thought it would only be at first, but she wouldn't let it go for even a moment, and I thought something was suspicious. I didn't want to suspect my wife, but I found some traces of deleted messages in the messages we exchanged, so I decided to ask an acquaintance who knows a lot about smartphones to restore the messages. Then I found out that my wife was having an affair. What's more, the other person was my classmate.