I tend to shy away from AIBU but in this case I truly want to know if I am in fact being unreasonable. I have a crap immune system so tend to catch any bug going around. We invited friends round last night and it was only when they got here that we found out one has a streaming cold. If I was invited somewhere I would at least let the hosts know that I was ill (but would probably duck out so I wouldn't pass the germs on). My MIL used to do the same, invite herself round and then announce that she has just been ill with d&v. I hate being exposed to bugs if I can help it so maybe I am being unreasonable?!