This first happened a few days ago when my sim, who's been happily married and settled for ages (and is neither flirty nor a hopeless romantic) was invited to a party. She was met at the door by the hostess and they chatted a minute, then there is a popup stating she was caught seeing another sim and is now labelled a cheat. I exited without saving, restarted and had to play that day again (this time someone else gave the party, but my sim did not attend). Today she got an opportunity at work (hospital) to improve relations with city hall by becoming good friends with a particular sim (a politician and already a friend); she went there after work, they talked a couple of minutes - career, politics, books, etc. - and there is that popup again "caught seeing another sim". I exited without saving. It now seems if she speaks to any sim in person she is "caught seeing another sim" (phone conversations apparently do not count). What is causing this idiocy and, more importantly, how do I stop it? Her life, and thus her spouse's, are on hold til this situation can be addressed.