This is an interesting question that applies to just about everyone. What do you do when a friend or family member asks to borrow some money from you? What is your rule? Or do you have one?
Personally, I try to avoid lending money to friends and especially relatives. However, I give the exception to the rule to immediate family. Why do I avoid lending money? No, i'm not greedy over my money, the fact of the matter is if you lend out money to your friends/family, you'll most likely never see it back. After a long period of non-payments, it may be awkward to keep hounding for payment. And what happens after that? The lender builds resentment and the relationship will inevitably turn sour.
That leads to me a story. A LONG time ago, my uncle borrowed a substantial amount of money from my Grandma and neglected to pay her back. This was about 20 years ago now, and guess what? Whenever my uncles name is mentioned around my Grandma, you can see her slowly clench her fist. Maybe that's an exaggeration, but my Grandma still to this day mentions my uncle in a negative light.
So that is why I don't lend out money to friends or family. Better to say no at the beginning than to destroy a relationship.
What is your money lending rule? And no, you can't borrow $20… :)