We're having dinner with some friends today. It has been in the diary for months as they are both ridiculously booked up. This morning one of my friends has just announced that some friends of hers are coming to visit her and could she bring them too? It's not as if we can really say no, and we probably won't have enough food as it's another 4 extra mouths to feed. It also kind of ruins the point as our friends will be chatting to their friends as obviously they won't know anyone and we'll basically be left as being a waitress and chef tasked with feeding them.
I may be old-fashioned but I think that if you are invited and accept, that invitation should take precedence over anything else, even if you think that something 'better' has come along.
I really feel like telling them where to go!