Internecine Female Vindictiveness
When one or more women derides another woman or group of women for not following a (often meaningless) social convention, generally motivated by obvious jealousy or an unwillingness to see someone of their own minority group get ahead. This is similar to the "crabs in a bucket" phenomenon where crabs will damage one another in order to be the last one killed.
Jennifer: "Did you see Kate all over that guy at the bar? What a slut! And she dresses so slutty too!"
Alex: "Geez, talk about your internecine female vindictiveness."
Alex: "Geez, talk about your internecine female vindictiveness."