Not sure if this has been mentioned before, because I couldn't find a thread on it.
My sim's house mate wanted to cast a "love charm" on her; but, since his skill level isn't so good it failed. Instead she got the moodlet "imminent nemesis" which said the first person to approach her, she would let them have it no matter who they were. The moodlet lasts 1 day unless someone approaches the sim.
The first time, her house mate started flirting with her and she beat him up and they became enemies. I didn't save and when I restarted, I kept him away from her. However, she went to work in one of the rabbit holes and became enemies with her boss who previously was her best friend!