From an article in 'The Guardian' (a prominent leftist British publication) by Ibn Warraq
Modern apologists of Islam try to downplay the evident materialism and sexual implications of such descriptions, but, as the Encyclopaedia of Islam says, even orthodox Muslim theologians such as al Ghazali (died 1111 CE) and Al-Ash'ari (died 935 CE) have "admitted sensual pleasures into paradise". The sensual pleasures are graphically elaborated by Al-Suyuti (died 1505 ), Koranic commentator and polymath. He wrote: "Each time we sleep with a houri we find her virgin. Besides, the penis of the Elected never softens. The erection is eternal; the sensation that you feel each time you make love is utterly delicious and out of this world and were you to experience it in this world you would faint. Each chosen one [ie Muslim] will marry seventy [sic] houris, besides the women he married on earth, and all will have appetising vaginas."