The 'it' being whether she, FIL and BIL are coming for Sunday lunch or not. She wants to wait and see what BIL fancies doing - if he wants to go out for the day we will all do that instead. But if he wants to come to our house they will. So I am supposed to shop for Sunday lunch for EIGHT without knowing if I am actually going to cook it or not. So am I being unreasonable in being slightly pissed off?