So I invited several friends round for something to eat tomorrow. A belated birthday celebration for me. One couple didn't reply to my invitation sent a week ago until midnight tonight and then asked if it was ok if they brought another person with them. I have spent all night preparing the food, starters for a certain number of people. I literally don't have the space or the plates, glasses etc for any more or the room at the table. Plus I dont know the other person so this will mean I will feel awkward and it will mean I don't enjoy my own party. So I have said no and said don't worry we will do it another time (as they kind of hinted this person was staying with them). AIBU?