Though we were prepared to say no you can't move into my house (click here for background post), we didn't have to say anything.
Unlike my sister-in-law who is quite oblivious to the obvious, my brother-in-law figured out that we weren't feeling that plan and went ahead and found an apartment for his family. No pouting or hard feelings or any of the dramatics we would have gotten had this been sister-in-law. They did ask us for help in selling some of their stuff on Craigslist and I've been posting pics and stuff for them and getting stuff sold.
And they did need a cash influx, which we gave, but even then, it was more, "whatever we could give them that wouldn't hurt us" rather than a demand for any specific amount.
It is their turn to host Thanksgiving and Christmas but we're doing it this year and we will be more generous with Christmas gifts for the kids than usual (I don't like to buy toys for children, so we tend to give books, sing-a-long CDs, dinosaur kits and stuff like that).
So no hard feelings or hate or anything.