A friend just dropped this one on me:

Friend (probably in my top 10 all time dogs, used to live together, only see each other occasionally as we live in different cities) calls me up out of the blue as I'm in the middle of something at work. Not the ideal time, obviously. She says that she has a huge favour to ask and I can say no if I want, I say fire away. Apparently, her brother is visiting her sister with his young family (wife + 1 baby), but the sister in question is pretty ill, so they don't want to stay at hers for fear of catching this bug. The favour is this - can my friend's brother stay at my house for two nights with his family?

I immediately thought... shit, I have to say yes and my weekend is ruined. Then she reiterated that I could say no, so I seized on it and said I wasn't comfortable having strangers in my house when I'll be out doing stuff, and it's a lot of unnecessary stress for the gf. She said fine, I shouldn't have asked, don't worry about it. But now I feel really guilty as I could have easily helped out these people who were in a bind. Anyway, I kind of thought it was a weird favour to ask.

Anyone asked you any big favours ever?