I told my girlfriend that my sister said that she (my girlfriend) doesn't actually love me and is just pretending to be in love. My girlfriend cried and said that I shouldn't rely on other people's judgement to understand her. Then she left. I'm not going to be seeing her in a week. What do I do now? She hasn't sent me any texts after that.
Did your sister tell you why she thought that? It's possible that your girlfriend is trying to manipulate you now, but it's hard to tell without more context.