No, it's not what you're thinking; get your mind out of the gutter! The various incarnations of Charlie's Angels are the stereotypical example of the Girl Threesome; each Threesome exemplifies a different combination of traits (The Bossy Girl, The Brainy Girl, the Flirty Girl; The Black Girl, The Caucasian Girl, The Asian Girl; etc.) 

Girl Threesomes don't just have to take one type of Threesome. One team could simultaneously be a Asian-Hispanic-Black Threesome and a Naive-Flirty-Streetwise Threesome, and they could all be Ass-Kicking Girls.