Someday maybe we will see accurate chimpanzee and bonobo ("pygmy chimpanzee" -- but they are not really smaller than common chimps)figures. Actually some bonobos have enormously long penises (when erect). But most are smaller and only in the human range (though they are always thin and pointed in apes). So maybe the human does have the longest penis ON AVERAGE. But anyway, yes the gorilla penis is quite small. Also, gorillas do not have sex very often and contact is brief, unlike our genetically closer cousins the chimp and bonobo.