A sexual position where the woman lays flat on her stomach with her legs together and the man, on his knees, stradles her legs just below the butt, sitcking his penis into her now tightly-squeezed vagina.
Janine was napping face down in the nude when Rick climbed on and gave her the prone bone.
Often mistaken for stories related to homosexual men the true meaning is usually set aside for the ignorant foreigners who generalized the meaning with out clearly thinking through (mostly Fat white Americans)
Yaoi considered to be the women's equivalent of the men's adapted erotic fiction. There are no sections identified as the Yaoi genre at the Comic Market but the books are there nevertheless (hidden within the adaptations and parodies genre and the fan club genre). Yaoi was originally an abbreviation for a self-mocking statement regarding erotic adaptations regardless of the gender of the creator. (Ya-O-I = "Yama nashi, Ochi nashi, Imi nashi" which means "No build up (in storytelling), no wrapping up (the conclusion), no real deep meaning (in doing the book)".) For whatever reason, the term now has attached itself with erotic adaptations and parodies created by women. The material that would be classified into this genre primarily involves gay relationships between the handsome or cute (male) characters. The genre tends to overlap with the adaptations and parodies genre, but this is not always the rule, for there is considerable crossover with the "June" category, as well as the fan club genres.
(borrowed from http://www.tc.umn.edu/~kane0034/doujin/jargon.htm )
A story about a man who uses his flexing biceps to find purpose of being buffed up.. that is so Yaoi.