My ds went to a girls party (in his class) recently and she had lots of class friends there, but not all the class (which is fine) but the mother had forgotten to give a piece of cake with the party bags, so she sent them into school the next day. As the teacher was letting them out at the end of the day, she was handing out the cake from the girls party to everyone who had been invited, and obviously left out the ones who hadn't, I thought that was not fair as some kids came out saying that they didn't get a piece.
On the other hand, only a hour ago my dd friends Dad pulled up outside our house asking if dd is going to his dd party next week as I hadn't replied, dd didn't even tell me she'd been invited.