He may not even realize how moochie he is being. Sometimes your friends get so used to you being generous, they start taking advantage on the grounds of familiarity. If he calls and you like smoking out with him, then do it, but tell his ass up front you need gas money and he needs to be paying for the McDonalds this time. If he can't handle that, then tell him just how you been feeling. Either he will straighten up and realize he is fucking over a friend, or he won't and you will know he isn't one.