Warning: This Math Joke is for Mature Audiences Only. If you are not mature enough to deal with adult themes please close your eyes while you read this joke.
A doctor, a lawyer, and a mathematician are having a discussion one day about whether or not it is better to have a wife or a girl friend.
The doctor points out that married men have more stable lives and tend to live longer than single men, so he concludes that it is better for a man to be married.
The lawyer points out that if your marriage does not work out your wife can get a divorce and take half of your stuff with her, but a girl friend can't, and so he concludes that it is better for a man to have a girl friend instead of a wife.
The mathematician says, "Do the Math!" "It is obviously better to have a wife and a girl friend!" The doctor and the lawyer ask him to explain why. "Well, when your wife thinks you are out running around with your girl friend, and your girl friend thinks you are home with your wife, you can sneak off to a quiet place and work on some Calculus!"