history: I am so sick of being used by my friends. I am done with them. I think all of my friends are just around for my money. I'm sure they're not - what makes you think that?
current: They never pay for anything and always look to me when the bill comes.
next: Perhaps next time the bill arrives, say something like, "ok, so that's $25 each" and take out $25 and put it on the table. They may take the hint.