I think it has something to do with making enemies with another Sim. I tried it once too and nothing happened, but the other day I started playing with a new family and right after moving them in, I got this message saying that my teen sim's classmate had started snubbing at her, and I looked at their friendship status or whatever it's called in the english version, and their relationship was almost as bad as it can be.
Which makes sense, because I think snubbing means like looking down on someone or humiliating them, right? Soeey, I have the spanish version... hehe.