A doctor, a lawyer and a mathematician were discussing the relative merits
of having a wife or a mistress.
The lawyer says: "For sure a mistress is better. If you have a wife and
want a divorce, it causes all sorts of legal problems.
The doctor says: "It's better to have a wife because the sense of security
lowers your stress and is good for your health.
The mathematician says: " You're both wrong. It's best to have both so that
when the wife thinks you're with the mistress and the mistress thinks you're
with your wife --- you can do some mathematics.
