I loaned money to a friend twice when he was hard up and I only ever asked him one time about getting it back. Ever since I just make him buy when we go out. I tell him he has to buy and that it's his interest on my loan! He laughs and we're still friends. If we stop for a snack, he pays. When we hit the bars he buys most of the rounds. If he's low on cash I buy of course, and often we just take turns buying rounds, that's what friends do, but overall I think he's paid me 10X over what I originally loaned him just on my bar bill!