DS has come home from school very upset today. Invitations were handed out some of the class last week to a child's birthday party, with the rest being handed out today. DS didn't have an invite in his bag and came home in tears. Explained it could be a numbers thing thinking that only some of class had been invited. Another mum asked if ds was going so as to double up on lifts and I said ds didn't get an invite. She was shocked as rest of class has been invited. Now I used to be friends with the child's mum and we drifted apart when boys were in different nursery sessions but to my knowledge there was no fall out. Because ds was so upset and as a result of what other mum said I texted birthday child's mum just to say something along the lines of"ds came home saying child was having a party but he didn't have an invite in his bag and wondered if ds had lost the invite and didn't want to appear rude by not replying if it has gone astray at school. Understand if it is a numbers thing and hope he has a great day" She has replied he isn't invited and it is a numbers thing. My issue is the whole class has been invited apart from ds and the venue does have a max number but it isn't so small that they would be struggling to invite ds (in my opinion). Am I being unreasonable to think that there is something odd going on?