Three NASA engineers, one from headquarters in Washington, one from the Johnson center in Houston, and one from the Jet Propulsion Laboratory (JPL) in Pasadena were discussing whether it was better to have a wife or a mistress.

The HQ guy said it was better to have a mistress, because they are more understanding of the long absences required of a NASA employee. The Johnson guy retorted, "Oh, no, one must always follow proper rules and procedures, and marriage is the proper procedure, so it is better to have a wife."

The JPL engineer replied, "No, it is better to have both. That way, you can tell your wife that you're with your mistress, your mistress that you're with your wife, and go to the lab and work."