My 18 yr old son's GF was supposed to come and stay this weekend. He now tells me she's ill. I have said I'd rather wait till next weekend as I'm already fighting a bug and don't want to be exposed to another while my immunity is low. He thinks I'm being totally unreasonable. He's also getting over an illness so says he doesn't feel up to going to stay with her. She's at uni so there are all the freshers flu going around . What do people think? Am I being selfish or sensible ?