I am having a Halloween party for 6 children and am really looking forward to it, have bought loads of decorations am planning some spooky games and of course trick or treating. My neices are two of the children and today their Mum tells me that theres something else they want to do in the evening now and so they will be leaving at 5.00, before its dark!. Im fuming inside as it totally changes things. I know its up to them and I cant force people to do what I want. But morally wants the right thing to do. Once you have accepted an invitation should you abide by it?