DONT GET IT!!!!!!

why is that someone in the fam has to always have a fav. its just not right and always have a 2 face on that person to like one day they wil tell you nice things then the next they are yelling at you nd saying mean things sometimes i just dont get them and the way that they act. and makes me think to what is she doing so right what has she ever done and way do they fav her so much i just dont get it