And who decides how much "desire" is the right amount? The messages popular culture is sending these days seem to indicate that women should want non-stop sex, and that there's something wrong with them if they don't. Strikes me as more in tune with young male fantasies than with biological reality or a healthy society.
The man involved, of course. The "right amount" is exactly the same level and timing as his ... no fair if she wants to be close friends when he wants to play a computer game.