My Sim constantly performs the React in Disgust animation, which in turn lowers the friendship bar to a point that I have to stay away from other sims in order to preserve the friendship bar. My Sims...
This only happens in my game, when I have cc pants or tops (less often) that used a nude mesh. So it's a good thing I prefer to use mostly official in game Maxis made stuff and only a small amount of cc :)