Lend your money and lose your friend.
Prov. You should not lend money to your friends; if you do, either you will have to bother your friend to repay the loan, which will make your friend resent you, or your friend will not repay the loan, which will make you resent your friend. Bill: Joe needs a hundred dollars to pay his landlord. I'm thinking about lending it to him. Alan: Lend your money and lose your friend.