I'm feeling a bit upset and think maybe I'm being over sensitive. My son turns five soon and I've invited about 20 of his friends to celebrate with him I can't invite all the class as its too expensive I've known one of his friends mum since he was born we are not particularly close but have always got on well or so I thought when we see each other outside the school gates we always chat anyway I invited her son to come to my sons party unfortunately they can't make it as they are busy and I have also invited her younger son to my daughters party which they did attend I have since found out she is holding a party for her son and my son is not invited I feel quite hurt by this am I being over sensitive?