Quanyou 7 Xiaoguo S01E05 - 一颗牙引发的出轨惨案

Fuxue, who claims to be a professional third-party investigator, finds a tooth at home, so she suspects his wife is cheating, and comes to the dental clinic to investigate the truth. His wife Xiaofeng happens to go to the clinic to find her good friend Wei Wei, and Xiaofeng reveals that the tooth is Fuxue himself. Yes, it was Chuuxue's tooth that was knocked out by others to protect Xiaofeng when she was young. Xiaofeng kept it all the time. After that, Fuuxue decided to switch to marriage crisis counseling.