Dear Matt,I've known quite a few folks like this — and your description sounds especially accurate.The Flaky Friend is a tough situation.  It's tough because, though you could easily push this person out of your life and be rid the nonsense … unless your mutual friends all do the same, you can find yourself being the one ostracized.

My advice:  be cordial to this person, but not overly so.  Don't do any favors (because you know they won't be returned).  Never give a "him or me" ultimatum to your friends (if he's attending something and you want a drama-less night, simply decline the invitation).

And be firm in your insistence that he remain at arm's length (meaning don't join any road trips in which he's involved — even as a passenger he's guaranteed to scramble up everyone's plans).

— M