http://en.wikipedia.org/wiki/Double_standard

The following extract from the above.

There is a subtle distinction to be made between double standards and hypocricy. The latter implies the acceptance of a single standard, but the disregard of it in practice. A man who believes that he has a right to have extra-marital affairs but his wife does not holds a double standard. A man who condemns all adultery while maintaining a mistress is a hypocrite.
ENDS