@moi
The Quran contains some graphic descriptions of these houris: transparent skin, big boobies, big eyes, "loving their husbands only", virginal, "untouched by man or jinn" so it most certainly can't be referring to grapes. Grapes that have big breasts? And love their husbands?
It's definitely referring to women and arithmetic doesn't matter because like happymurtad pointed out they're Allah's celestial hoes created specifically to service pious Muslim men in the afterlife. Allah just snaps his fingers and shit is created so the technicalities/mathematics aren't a problem at all.
Seeing as the Quran was written by a 7th century Arab man/men it's no suprise that heaven is all about sex, wine, rivers, gardens, etc because that shit appealed to those dudes, although sex is a universal pleasure. The Quran very rarely addresses women and it's written by a man/men hence the lack of attention given to what women will get in heaven.