Perhaps sometimes you're wearing make-up and are therefore more sexually attractive to men and therefore you laugh less because you're less jealous?

Jokes are all about context, and whether or not you think someone believes that women are inferior, and how much their opinion matters will affect how jokes are received. There was actually a rather good article in the collection about jokes as social tool for controlling deviance talking about groups of feminist women laughing at chauvinism jokes when they thought that the teller agreed with them that they were wrong, and glaring when they thought the teller believed in the inferiority of women.