Young men don't read this

Libido lags for ladies in luck | Health | The Australian

From the above article:

THE female sex drive starts sputtering to a halt as soon as a woman has got her man, according to a new study.

Researchers have found that women's libido plummets so rapidly when they believe they are in a secure relationship that after just four years the proportion of 30-year-old women wanting regular sex falls below 50 percent.

There are few things that appear able to keep a woman sexually interested, the study found, but living apart for extended periods can help.

(But - surely living apart for extended periods must also run a much increased risk of infidelity, which tends not to help the sex life back at home.)

Back to the story:

The findings for women contrast with those for men, whose sexual appetite hardly flagged at all up to 40 years after marriage.

"Male motivation remains constant regardless of the duration of the partnership." Dr Klusmann questioned more than 500 people about their sex lives in order to measure changes in their libido.

He found that within a year of a relationship starting, female libido moved into steep decline.

While 60 per cent of 30-year-old women reported wanting sex "often" at the start of a relationship, the figure fell to below 50per cent within four years and to about 20 per cent after 20 years.