Mother of child in my son's class - did you REALLY have to give out your DD's party invitations to all and sundry (including the other child I take to school)in the line just before school? DS has only started school and was very upset. He then started opening an imaginary invitation and pretending he really had been invited and went sadly into class.
Yes, yes I know this is the real world and he can't be invited to everything, nor should he be, but let's face it - even at our age being left out still sucks and he is only 5. He probably won't be invited to many things as he is eccentric and nerdy 
AIBU to imagine kicking that mother up the arse? I can't help it - it set him up for a crap start to his day. GRR!