Grinbitch
And what vulgarities are you girls talking about today? Pet name given to Haruka Kyogokuin by /b/, a character from an incestual lolicon manga called Papa Nanka Daikirai. Like pretty much all the little girls in the manga she has sex with her father; in her case the sex is not entirely consensual (her father uses her as a replacement for her mother, who walked out on him). She also fulfills the "stuck-up, rich classmate" role, and is gay for a tomboyish classmate named Otome, with whom she has a love/hate relationship; the two girls are arch-enemies at the start of the manga, Otome eventually starts reaching out to Haruka, sensing her need for a friend, and ultimately Haruka and Otome wind up having sex at a slumber party. Her fame stems from a cropped image of her in which she says "Oh ho, why not whore ourselves?" while holding her hand to her face in an arrogant pose and smiling in a bemused, condescending manner.
That is the question. This evolved into macros of other characters with similar facial expressions and captions with some form of "oh ho, why not ourselves". Ironically, this phrase is actually a mistranslation of the original Japanese text (in which she says "Oh ho, are you trying to sell a fight?").