But in these stories, especially the later ones, he seems to have been unable to get beyond his own commonplace fantasies about prostitutes and 1960s miniskirts.
He has a fetish for prostitutes and skirts. 
mnli hypothesis: He has a fetish for prostitutes and skirts.  premise: But in these stories, especially the later ones, he seems to have been unable to get beyond his own commonplace fantasies about prostitutes and 1960s miniskirts.