The difference could be less in libido and more in the general state one finishes the day. After a series of 12~14h work day for example, you're usually not lon

The difference could be less in libido and more in the general state one finishes the day. After a series of 12~14h work day for example, you're usually not longing for a night of sex. Now there must be thousands of other possible factors, but it is commonly accepted as a stereotype that 10 or 20 years couple would be sexless.