Long post!!! Okay, so a little backstory is required. I'll try to make it quick, promise!   So my BIL (my fiances older brother) graduated college in May. He needed somewhere to stay for a few months until he could start a career pertaining to his degree. Cool, my fiance and I have our own house with a spare bedroom, so we welcome him in. In the very beginning we lay down that he would only be staying for 3 months but for 5 months ABSOLUTE MAX.   It is now November, and my fiance and I are ready to move to a new house (we rent, btw) and are on the search. 

 I find the most perfect house for us and my BIL tours it with me and he sees how in love I and his brother are with this house. The only problem is that my fiance doesn't have great credit due to some past complications with the military, so there isn't a good chance of him being approved by the owner. We easily make the rent requirement, it's just that pesky credit. 

 That's fine, my credit is good and so is my BIL's, so we ask him to think about putting his name on the new lease, since he would be MOVING WITH US INTO A NEW HOUSE FOR A LONGER PERIOD OF TIME (hence over staying his welcome by even longer) and would be living there for the lease period. He thinks about it for a few days and eventually tells us no because "he doesn't want to put his name on something he doesn't understand" (?) and because “every horror story you hear is about a 20 year old who trusted someone with his credit” (???)  

 We are so livid that he has forgotten the tremendous favor we have done for him, because he has literally no friends or family he could stay with and makes absolutely no money to get his own place at his shitty waiter job. When I confronted him about not signing the lease, he tried to be a smart ass and he got extremely defensive, to the point where the conversation was unsalvageable (he's the kind of person where he is NEVER wrong). 

 We are currently looking for a new place to live so we can kick him out. Am I the asshole for being pissed beyond belief and wanting to kick him out and honestly not caring what's next for him?