Valentine Sex
As an easy way to save money, a young couple decided that every time they have sex the husband would put his pocket change into a piggy bank on the nightstand. On Valentine's night, he was unusually athletic and accidentally knocked the piggy bank off the table and it broke into pieces on the floor.
To his surprise, among the masses of coins, there are handfuls of five and ten and even twenty dollar bills. He asks his wife "What's up with all the paper money?", to his wife which replied, "Well, not everyone is as cheap as you are."