1) They will think that since you are friends then they can get away with damn near anything.
2) They will take advantage of you.
3) They will expect you to be their maid.
4) They will eat all of your food but get mad when you eat something of theirs.
5) The "it wasn't me ghost" makes an appearance any time something happens and no one wants to admit to doing it.
6) Even though you are the one helping them out by giving them a place to stay, they will tell all friends that it is them doing the helping.
7) They will talk badly about you when you ask for rent.
8) It will ruin your friendship no matter how close you were.
Add your own!!!!